/*
  * MJPEG decoder

  * Copyright (c) 2000, 2001 Fabrice Bellard

  * Copyright (c) 2003 Alex Beregszaszi
  * Copyright (c) 2003-2004 Michael Niedermayer
  *

  * Support for external huffman table, various fixes (AVID workaround),
  * aspecting, new decode_frame mechanism and apple mjpeg-b support
  *                                  by Alex Beregszaszi
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**

  * @file

  * MJPEG decoder.
  */
 

 // #define DEBUG

 #include <assert.h>
 

 #include "libavutil/imgutils.h"

 #include "libavutil/avassert.h"

 #include "libavutil/opt.h"

 #include "avcodec.h"
 #include "dsputil.h"
 #include "mjpeg.h"

 #include "mjpegdec.h"

 #include "jpeglsdec.h"
 
 

 static int build_vlc(VLC *vlc, const uint8_t *bits_table,
                      const uint8_t *val_table, int nb_codes,
                      int use_static, int is_ac)

 {

     uint8_t huff_size[256] = { 0 };

     uint16_t huff_code[256];
     uint16_t huff_sym[256];
     int i;

 
     assert(nb_codes <= 256);
 

     ff_mjpeg_build_huffman_codes(huff_size, huff_code, bits_table, val_table);

     for (i = 0; i < 256; i++)
         huff_sym[i] = i + 16 * is_ac;

     if (is_ac)
         huff_sym[0] = 16 * 256;

     return ff_init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1,
                               huff_code, 2, 2, huff_sym, 2, 2, use_static);

 }
 

 static void build_basic_mjpeg_vlc(MJpegDecodeContext *s)
 {

     build_vlc(&s->vlcs[0][0], ff_mjpeg_bits_dc_luminance,

               ff_mjpeg_val_dc, 12, 0, 0);

     build_vlc(&s->vlcs[0][1], ff_mjpeg_bits_dc_chrominance,

               ff_mjpeg_val_dc, 12, 0, 0);

     build_vlc(&s->vlcs[1][0], ff_mjpeg_bits_ac_luminance,
               ff_mjpeg_val_ac_luminance, 251, 0, 1);
     build_vlc(&s->vlcs[1][1], ff_mjpeg_bits_ac_chrominance,
               ff_mjpeg_val_ac_chrominance, 251, 0, 1);

     build_vlc(&s->vlcs[2][0], ff_mjpeg_bits_ac_luminance,
               ff_mjpeg_val_ac_luminance, 251, 0, 0);
     build_vlc(&s->vlcs[2][1], ff_mjpeg_bits_ac_chrominance,
               ff_mjpeg_val_ac_chrominance, 251, 0, 0);

 }
 

 av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)

 {
     MJpegDecodeContext *s = avctx->priv_data;
 

     if (!s->picture_ptr)
         s->picture_ptr = &s->picture;

     avcodec_get_frame_defaults(&s->picture);

     s->avctx = avctx;

     ff_dsputil_init(&s->dsp, avctx);

     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);

     s->buffer_size   = 0;
     s->buffer        = NULL;
     s->start_code    = -1;

     s->first_picture = 1;

     s->org_height    = avctx->coded_height;

     avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;

     build_basic_mjpeg_vlc(s);

     if (s->extern_huff) {

         av_log(avctx, AV_LOG_INFO, "mjpeg: using external huffman table\n");

         init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);

         if (ff_mjpeg_decode_dht(s)) {

             av_log(avctx, AV_LOG_ERROR,
                    "mjpeg: error using external huffman table, switching back to internal\n");

             build_basic_mjpeg_vlc(s);

         }

     }

     if (avctx->field_order == AV_FIELD_BB) { /* quicktime icefloe 019 */

         s->interlace_polarity = 1;           /* bottom field first */

         av_log(avctx, AV_LOG_DEBUG, "mjpeg bottom field first\n");

     }

     if (avctx->codec->id == CODEC_ID_AMV)
         s->flipped = 1;

 
     return 0;
 }
 
 
 /* quantize tables */

 int ff_mjpeg_decode_dqt(MJpegDecodeContext *s)

 {
     int len, index, i, j;
 
     len = get_bits(&s->gb, 16) - 2;
 
     while (len >= 65) {
         /* only 8 bit precision handled */

         if (get_bits(&s->gb, 4) != 0) {

             av_log(s->avctx, AV_LOG_ERROR, "dqt: 16bit precision\n");
             return -1;
         }
         index = get_bits(&s->gb, 4);
         if (index >= 4)
             return -1;
         av_log(s->avctx, AV_LOG_DEBUG, "index=%d\n", index);
         /* read quant table */

         for (i = 0; i < 64; i++) {

             j = s->scantable.permutated[i];
             s->quant_matrixes[index][j] = get_bits(&s->gb, 8);
         }
 

         // XXX FIXME finetune, and perhaps add dc too
         s->qscale[index] = FFMAX(s->quant_matrixes[index][s->scantable.permutated[1]],
                                  s->quant_matrixes[index][s->scantable.permutated[8]]) >> 1;
         av_log(s->avctx, AV_LOG_DEBUG, "qscale[%d]: %d\n",
                index, s->qscale[index]);

         len -= 65;
     }
     return 0;
 }
 
 /* decode huffman tables and build VLC decoders */

 int ff_mjpeg_decode_dht(MJpegDecodeContext *s)

 {
     int len, index, i, class, n, v, code_max;
     uint8_t bits_table[17];
     uint8_t val_table[256];
 
     len = get_bits(&s->gb, 16) - 2;
 
     while (len > 0) {
         if (len < 17)
             return -1;
         class = get_bits(&s->gb, 4);
         if (class >= 2)
             return -1;
         index = get_bits(&s->gb, 4);
         if (index >= 4)
             return -1;
         n = 0;

         for (i = 1; i <= 16; i++) {

             bits_table[i] = get_bits(&s->gb, 8);
             n += bits_table[i];
         }
         len -= 17;
         if (len < n || n > 256)
             return -1;
 
         code_max = 0;

         for (i = 0; i < n; i++) {

             v = get_bits(&s->gb, 8);
             if (v > code_max)
                 code_max = v;
             val_table[i] = v;
         }
         len -= n;
 
         /* build VLC and flush previous vlc if present */

         ff_free_vlc(&s->vlcs[class][index]);

         av_log(s->avctx, AV_LOG_DEBUG, "class=%d index=%d nb_codes=%d\n",
                class, index, code_max + 1);

         if (build_vlc(&s->vlcs[class][index], bits_table, val_table,
                       code_max + 1, 0, class > 0) < 0)

             return -1;

         if (class > 0) {

             ff_free_vlc(&s->vlcs[2][index]);

             if (build_vlc(&s->vlcs[2][index], bits_table, val_table,
                           code_max + 1, 0, 0) < 0)
                 return -1;

         }

     }
     return 0;
 }
 

 int ff_mjpeg_decode_sof(MJpegDecodeContext *s)

 {
     int len, nb_components, i, width, height, pix_fmt_id;
 

     s->cur_scan = 0;

     s->upscale_h = s->upscale_v = 0;

     /* XXX: verify len field validity */

     len     = get_bits(&s->gb, 16);
     s->bits = get_bits(&s->gb, 8);

     if (s->pegasus_rct)
         s->bits = 9;
     if (s->bits == 9 && !s->pegasus_rct)
         s->rct  = 1;    // FIXME ugly

     if (s->bits != 8 && !s->lossless) {

         av_log(s->avctx, AV_LOG_ERROR, "only 8 bits/component accepted\n");
         return -1;
     }
 

     if(s->lossless && s->avctx->lowres){
         av_log(s->avctx, AV_LOG_ERROR, "lowres is not possible with lossless jpeg\n");
         return -1;
     }
 

     height = get_bits(&s->gb, 16);

     width  = get_bits(&s->gb, 16);

     // HACK for odd_height.mov
     if (s->interlaced && s->width == width && s->height == height + 1)

         height= s->height;
 
     av_log(s->avctx, AV_LOG_DEBUG, "sof0: picture: %dx%d\n", width, height);

     if (av_image_check_size(width, height, 0, s->avctx))

         return -1;
 
     nb_components = get_bits(&s->gb, 8);
     if (nb_components <= 0 ||
         nb_components > MAX_COMPONENTS)
         return -1;

     if (s->interlaced && (s->bottom_field == !s->interlace_polarity)) {
         if (nb_components != s->nb_components) {
             av_log(s->avctx, AV_LOG_ERROR, "nb_components changing in interlaced picture\n");
             return AVERROR_INVALIDDATA;
         }
     }

     if (s->ls && !(s->bits <= 8 || nb_components == 1)) {
         av_log(s->avctx, AV_LOG_ERROR,
                "only <= 8 bits/component or 16-bit gray accepted for JPEG-LS\n");

         return -1;
     }
     s->nb_components = nb_components;

     s->h_max         = 1;
     s->v_max         = 1;
     for (i = 0; i < nb_components; i++) {

         /* component id */
         s->component_id[i] = get_bits(&s->gb, 8) - 1;

         s->h_count[i]      = get_bits(&s->gb, 4);
         s->v_count[i]      = get_bits(&s->gb, 4);

         /* compute hmax and vmax (only used in interleaved case) */
         if (s->h_count[i] > s->h_max)
             s->h_max = s->h_count[i];
         if (s->v_count[i] > s->v_max)
             s->v_max = s->v_count[i];

         if (!s->h_count[i] || !s->v_count[i]) {
             av_log(s->avctx, AV_LOG_ERROR, "h/v_count is 0\n");
             return -1;
         }

         s->quant_index[i] = get_bits(&s->gb, 8);
         if (s->quant_index[i] >= 4)
             return -1;

         av_log(s->avctx, AV_LOG_DEBUG, "component %d %d:%d id: %d quant:%d\n",
                i, s->h_count[i], s->v_count[i],
                s->component_id[i], s->quant_index[i]);

     }
 

     if (s->ls && (s->h_max > 1 || s->v_max > 1)) {
         av_log(s->avctx, AV_LOG_ERROR,
                "Subsampling in JPEG-LS is not supported.\n");

         return -1;
     }
 

     if (s->v_max == 1 && s->h_max == 1 && s->lossless==1 && nb_components==3)
         s->rgb = 1;

 
     /* if different size, realloc/alloc picture */
     /* XXX: also check h_count and v_count */
     if (width != s->width || height != s->height) {
         av_freep(&s->qscale_table);
 

         s->width      = width;
         s->height     = height;

         s->interlaced = 0;
 
         /* test interlaced mode */

         if (s->first_picture   &&

             s->org_height != 0 &&
             s->height < ((s->org_height * 3) / 4)) {

             s->interlaced                    = 1;
             s->bottom_field                  = s->interlace_polarity;

             s->picture_ptr->interlaced_frame = 1;

             s->picture_ptr->top_field_first  = !s->interlace_polarity;

             height *= 2;
         }
 
         avcodec_set_dimensions(s->avctx, width, height);
 

         s->qscale_table  = av_mallocz((s->width + 15) / 16);

         s->first_picture = 0;
     }
 

     if (s->interlaced && (s->bottom_field == !s->interlace_polarity)) {
         if (s->progressive) {
             av_log_ask_for_sample(s->avctx, "progressively coded interlaced pictures not supported\n");
             return AVERROR_INVALIDDATA;
         }

     } else{

     /* XXX: not complete test ! */

     pix_fmt_id = (s->h_count[0] << 28) | (s->v_count[0] << 24) |
                  (s->h_count[1] << 20) | (s->v_count[1] << 16) |
                  (s->h_count[2] << 12) | (s->v_count[2] <<  8) |
                  (s->h_count[3] <<  4) |  s->v_count[3];

     av_log(s->avctx, AV_LOG_DEBUG, "pix fmt id %x\n", pix_fmt_id);

     /* NOTE we do not allocate pictures large enough for the possible
      * padding of h/v_count being 4 */
     if (!(pix_fmt_id & 0xD0D0D0D0))
         pix_fmt_id -= (pix_fmt_id & 0xF0F0F0F0) >> 1;
     if (!(pix_fmt_id & 0x0D0D0D0D))
         pix_fmt_id -= (pix_fmt_id & 0x0F0F0F0F) >> 1;
 
     switch (pix_fmt_id) {

     case 0x11111100:

         if (s->rgb)

             s->avctx->pix_fmt = PIX_FMT_BGR24;

         else {
             if (s->component_id[0] == 'Q' && s->component_id[1] == 'F' && s->component_id[2] == 'A') {

                 s->avctx->pix_fmt = PIX_FMT_GBR24P;

             } else {

             s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV444P : PIX_FMT_YUVJ444P;

             s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;

             }

         }

         assert(s->nb_components == 3);

         break;

     case 0x12121100:

     case 0x22122100:

         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV444P : PIX_FMT_YUVJ444P;
         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;

         s->upscale_v = 2;
         s->upscale_h = (pix_fmt_id == 0x22122100);
         s->chroma_height = s->height;
         break;
     case 0x21211100:
     case 0x22211200:
         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV444P : PIX_FMT_YUVJ444P;
         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;
         s->upscale_v = (pix_fmt_id == 0x22211200);
         s->upscale_h = 2;
         s->chroma_height = s->height;
         break;
     case 0x22221100:
         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV444P : PIX_FMT_YUVJ444P;
         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;
         s->upscale_v = 2;
         s->upscale_h = 2;
         s->chroma_height = s->height / 2;

         break;

     case 0x11000000:

         if(s->bits <= 8)
             s->avctx->pix_fmt = PIX_FMT_GRAY8;
         else
             s->avctx->pix_fmt = PIX_FMT_GRAY16;

         break;

     case 0x12111100:

     case 0x22211100:

     case 0x22112100:

         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV440P : PIX_FMT_YUVJ440P;

         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;

         s->upscale_h = (pix_fmt_id == 0x22211100) * 2 + (pix_fmt_id == 0x22112100);
         s->chroma_height = s->height / 2;

         break;

     case 0x21111100:

         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV422P : PIX_FMT_YUVJ422P;

         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;

         break;

     case 0x22121100:
     case 0x22111200:
         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV422P : PIX_FMT_YUVJ422P;
         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;
         s->upscale_v = (pix_fmt_id == 0x22121100) + 1;
         break;

     case 0x22111100:

         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV420P : PIX_FMT_YUVJ420P;

         s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;

         break;

     default:
         av_log(s->avctx, AV_LOG_ERROR, "Unhandled pixel format 0x%x\n", pix_fmt_id);
         return -1;

     }

     if ((s->upscale_h || s->upscale_v) && s->avctx->lowres) {
         av_log(s->avctx, AV_LOG_ERROR, "lowres not supported for weird subsampling\n");
         return AVERROR_PATCHWELCOME;
     }

     if (s->ls) {

         s->upscale_h = s->upscale_v = 0;

         if (s->nb_components > 1)

             s->avctx->pix_fmt = PIX_FMT_RGB24;

         else if (s->bits <= 8)

             s->avctx->pix_fmt = PIX_FMT_GRAY8;
         else
             s->avctx->pix_fmt = PIX_FMT_GRAY16;
     }
 

     if (s->picture_ptr->data[0])

         s->avctx->release_buffer(s->avctx, s->picture_ptr);

     if (s->avctx->get_buffer(s->avctx, s->picture_ptr) < 0) {

         av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return -1;
     }

     s->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
     s->picture_ptr->key_frame = 1;
     s->got_picture            = 1;

     for (i = 0; i < 3; i++)
         s->linesize[i] = s->picture_ptr->linesize[i] << s->interlaced;

 //    printf("%d %d %d %d %d %d\n",
 //           s->width, s->height, s->linesize[0], s->linesize[1],
 //           s->interlaced, s->avctx->height);

     if (len != (8 + (3 * nb_components)))

         av_log(s->avctx, AV_LOG_DEBUG, "decode_sof0: error, len(%d) mismatch\n", len);

     }

 
     /* totally blank picture as progressive JPEG will only add details to it */

     if (s->progressive) {
         int bw = (width  + s->h_max * 8 - 1) / (s->h_max * 8);
         int bh = (height + s->v_max * 8 - 1) / (s->v_max * 8);
         for (i = 0; i < s->nb_components; i++) {

             int size = bw * bh * s->h_count[i] * s->v_count[i];
             av_freep(&s->blocks[i]);
             av_freep(&s->last_nnz[i]);

             s->blocks[i]       = av_malloc(size * sizeof(**s->blocks));
             s->last_nnz[i]     = av_mallocz(size * sizeof(**s->last_nnz));

             s->block_stride[i] = bw * s->h_count[i];
         }
         memset(s->coefs_finished, 0, sizeof(s->coefs_finished));

     }
     return 0;
 }
 
 static inline int mjpeg_decode_dc(MJpegDecodeContext *s, int dc_index)
 {
     int code;
     code = get_vlc2(&s->gb, s->vlcs[0][dc_index].table, 9, 2);

     if (code < 0) {
         av_log(s->avctx, AV_LOG_WARNING,
                "mjpeg_decode_dc: bad vlc: %d:%d (%p)\n",
                0, dc_index, &s->vlcs[0][dc_index]);

         return 0xffff;
     }
 

     if (code)

         return get_xbits(&s->gb, code);
     else
         return 0;
 }
 
 /* decode block and dequantize */

 static int decode_block(MJpegDecodeContext *s, DCTELEM *block, int component,
                         int dc_index, int ac_index, int16_t *quant_matrix)

 {
     int code, i, j, level, val;
 
     /* DC coef */
     val = mjpeg_decode_dc(s, dc_index);
     if (val == 0xffff) {
         av_log(s->avctx, AV_LOG_ERROR, "error dc\n");
         return -1;
     }
     val = val * quant_matrix[0] + s->last_dc[component];
     s->last_dc[component] = val;
     block[0] = val;
     /* AC coefs */
     i = 0;

     {OPEN_READER(re, &s->gb);

     do {

         UPDATE_CACHE(re, &s->gb);

         GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2);

 
         i += ((unsigned)code) >> 4;
             code &= 0xf;

         if (code) {
             if (code > MIN_CACHE_BITS - 16)

                 UPDATE_CACHE(re, &s->gb);

             {

                 int cache = GET_CACHE(re, &s->gb);
                 int sign  = (~cache) >> 31;
                 level     = (NEG_USR32(sign ^ cache,code) ^ sign) - sign;

             }
 

             LAST_SKIP_BITS(re, &s->gb, code);

             if (i > 63) {

                 av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);
                 return -1;
             }

             j        = s->scantable.permutated[i];

             block[j] = level * quant_matrix[j];
         }

     } while (i < 63);

     CLOSE_READER(re, &s->gb);}

 
     return 0;
 }
 

 static int decode_dc_progressive(MJpegDecodeContext *s, DCTELEM *block,
                                  int component, int dc_index,
                                  int16_t *quant_matrix, int Al)

 {
     int val;

     s->dsp.clear_block(block);

     val = mjpeg_decode_dc(s, dc_index);
     if (val == 0xffff) {
         av_log(s->avctx, AV_LOG_ERROR, "error dc\n");
         return -1;
     }
     val = (val * quant_matrix[0] << Al) + s->last_dc[component];
     s->last_dc[component] = val;
     block[0] = val;
     return 0;
 }
 

 /* decode block and dequantize - progressive JPEG version */

 static int decode_block_progressive(MJpegDecodeContext *s, DCTELEM *block,
                                     uint8_t *last_nnz, int ac_index,
                                     int16_t *quant_matrix,

                                     int ss, int se, int Al, int *EOBRUN)

 {
     int code, i, j, level, val, run;
 

     if (*EOBRUN) {

         (*EOBRUN)--;
         return 0;
     }

     {
         OPEN_READER(re, &s->gb);
         for (i = ss; ; i++) {
             UPDATE_CACHE(re, &s->gb);
             GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2);

             run = ((unsigned) code) >> 4;
             code &= 0xF;
             if (code) {
                 i += run;
                 if (code > MIN_CACHE_BITS - 16)
                     UPDATE_CACHE(re, &s->gb);

                 {
                     int cache = GET_CACHE(re, &s->gb);
                     int sign  = (~cache) >> 31;
                     level     = (NEG_USR32(sign ^ cache,code) ^ sign) - sign;

                 }

 
                 LAST_SKIP_BITS(re, &s->gb, code);
 

                 if (i >= se) {

                     if (i == se) {
                         j = s->scantable.permutated[se];
                         block[j] = level * quant_matrix[j] << Al;
                         break;
                     }
                     av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);

                     return -1;
                 }

                 j = s->scantable.permutated[i];
                 block[j] = level * quant_matrix[j] << Al;
             } else {
                 if (run == 0xF) {// ZRL - skip 15 coefficients
                     i += 15;
                     if (i >= se) {
                         av_log(s->avctx, AV_LOG_ERROR, "ZRL overflow: %d\n", i);
                         return -1;
                     }
                 } else {
                     val = (1 << run);
                     if (run) {
                         UPDATE_CACHE(re, &s->gb);
                         val += NEG_USR32(GET_CACHE(re, &s->gb), run);
                         LAST_SKIP_BITS(re, &s->gb, run);
                     }
                     *EOBRUN = val - 1;
                     break;

                 }

             }
         }

         CLOSE_READER(re, &s->gb);

     }

 
     if (i > *last_nnz)

         *last_nnz = i;

     return 0;
 }
 

 #define REFINE_BIT(j) {                                             \
     UPDATE_CACHE(re, &s->gb);                                       \
     sign = block[j] >> 15;                                          \
     block[j] += SHOW_UBITS(re, &s->gb, 1) *                         \
                 ((quant_matrix[j] ^ sign) - sign) << Al;            \
     LAST_SKIP_BITS(re, &s->gb, 1);                                  \

 }
 

 #define ZERO_RUN                                                    \
 for (; ; i++) {                                                     \
     if (i > last) {                                                 \
         i += run;                                                   \
         if (i > se) {                                               \
             av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i); \
             return -1;                                              \
         }                                                           \
         break;                                                      \
     }                                                               \
     j = s->scantable.permutated[i];                                 \
     if (block[j])                                                   \
         REFINE_BIT(j)                                               \
     else if (run-- == 0)                                            \
         break;                                                      \

 }
 
 /* decode block and dequantize - progressive JPEG refinement pass */

 static int decode_block_refinement(MJpegDecodeContext *s, DCTELEM *block,
                                    uint8_t *last_nnz,
                                    int ac_index, int16_t *quant_matrix,
                                    int ss, int se, int Al, int *EOBRUN)

 {

     int code, i = ss, j, sign, val, run;
     int last    = FFMIN(se, *last_nnz);

 
     OPEN_READER(re, &s->gb);

     if (*EOBRUN) {

         (*EOBRUN)--;

     } else {
         for (; ; i++) {

             UPDATE_CACHE(re, &s->gb);

             GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2);

             if (code & 0xF) {

                 run = ((unsigned) code) >> 4;
                 UPDATE_CACHE(re, &s->gb);
                 val = SHOW_UBITS(re, &s->gb, 1);
                 LAST_SKIP_BITS(re, &s->gb, 1);
                 ZERO_RUN;
                 j = s->scantable.permutated[i];
                 val--;

                 block[j] = ((quant_matrix[j]^val) - val) << Al;
                 if (i == se) {
                     if (i > *last_nnz)

                         *last_nnz = i;

                     CLOSE_READER(re, &s->gb);

                     return 0;
                 }

             } else {

                 run = ((unsigned) code) >> 4;

                 if (run == 0xF) {

                     ZERO_RUN;

                 } else {

                     val = run;
                     run = (1 << run);

                     if (val) {

                         UPDATE_CACHE(re, &s->gb);
                         run += SHOW_UBITS(re, &s->gb, val);
                         LAST_SKIP_BITS(re, &s->gb, val);
                     }
                     *EOBRUN = run - 1;
                     break;
                 }
             }
         }
 

         if (i > *last_nnz)

             *last_nnz = i;
     }
 

     for (; i <= last; i++) {

         j = s->scantable.permutated[i];

         if (block[j])

             REFINE_BIT(j)
     }
     CLOSE_READER(re, &s->gb);

 
     return 0;
 }

 #undef REFINE_BIT
 #undef ZERO_RUN

 static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int nb_components, int predictor, int point_transform)
 {

     int i, mb_x, mb_y;

     uint16_t (*buffer)[4];

     int left[3], top[3], topleft[3];

     const int linesize = s->linesize[0];
     const int mask     = (1 << s->bits) - 1;

     int resync_mb_y = 0;
     int resync_mb_x = 0;

     s->restart_count = s->restart_interval;
 

     av_fast_malloc(&s->ljpeg_buffer, &s->ljpeg_buffer_size,
                    (unsigned)s->mb_width * 4 * sizeof(s->ljpeg_buffer[0][0]));
     buffer = s->ljpeg_buffer;

     for (i = 0; i < 3; i++)
         buffer[0][i] = 1 << (s->bits - 1);
 
     for (mb_y = 0; mb_y < s->mb_height; mb_y++) {

         uint8_t *ptr = s->picture.data[0] + (linesize * mb_y);
 
         if (s->interlaced && s->bottom_field)
             ptr += linesize >> 1;
 

         for (i = 0; i < 3; i++)
             top[i] = left[i] = topleft[i] = buffer[0][i];
 
         for (mb_x = 0; mb_x < s->mb_width; mb_x++) {

             int modified_predictor = predictor;
 
             if (s->restart_interval && !s->restart_count){

                 s->restart_count = s->restart_interval;

                 resync_mb_x = mb_x;
                 resync_mb_y = mb_y;
                 for(i=0; i<3; i++)

                     top[i] = left[i]= topleft[i]= 1 << (s->bits - 1);

             }

             if (mb_y == resync_mb_y || mb_y == resync_mb_y+1 && mb_x < resync_mb_x || !mb_x)

                 modified_predictor = 1;

             for (i=0;i<nb_components;i++) {

                 int pred, dc;

                 topleft[i] = top[i];
                 top[i]     = buffer[mb_x][i];

 
                 PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
 

                 dc = mjpeg_decode_dc(s, s->dc_index[i]);
                 if(dc == 0xFFFF)
                     return -1;
 

                 left[i] = buffer[mb_x][i] =
                     mask & (pred + (dc << point_transform));

             }
 
             if (s->restart_interval && !--s->restart_count) {
                 align_get_bits(&s->gb);
                 skip_bits(&s->gb, 16); /* skip RSTn */
             }
         }
 

         if (s->rct) {
             for (mb_x = 0; mb_x < s->mb_width; mb_x++) {
                 ptr[3*mb_x + 1] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2] - 0x200) >> 2);
                 ptr[3*mb_x + 0] = buffer[mb_x][1] + ptr[3*mb_x + 1];
                 ptr[3*mb_x + 2] = buffer[mb_x][2] + ptr[3*mb_x + 1];

             }

         } else if (s->pegasus_rct) {
             for (mb_x = 0; mb_x < s->mb_width; mb_x++) {
                 ptr[3*mb_x + 1] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2]) >> 2);
                 ptr[3*mb_x + 0] = buffer[mb_x][1] + ptr[3*mb_x + 1];
                 ptr[3*mb_x + 2] = buffer[mb_x][2] + ptr[3*mb_x + 1];

             }

         } else {
             for(i=0; i<nb_components; i++) {

                 int c= s->comp_index[i];
                 for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
                     ptr[3*mb_x+2-c] = buffer[mb_x][i];
                 }

             }
         }
     }
     return 0;
 }
 

 static int ljpeg_decode_yuv_scan(MJpegDecodeContext *s, int predictor,
                                  int point_transform)
 {

     int i, mb_x, mb_y;

     const int nb_components=s->nb_components;
     int bits= (s->bits+7)&~7;

     int resync_mb_y = 0;
     int resync_mb_x = 0;

 
     point_transform += bits - s->bits;
 
     av_assert0(nb_components==1 || nb_components==3);

     for (mb_y = 0; mb_y < s->mb_height; mb_y++) {
         for (mb_x = 0; mb_x < s->mb_width; mb_x++) {

             if (s->restart_interval && !s->restart_count){

                 s->restart_count = s->restart_interval;

                 resync_mb_x = mb_x;
                 resync_mb_y = mb_y;
             }

             if(!mb_x || mb_y == resync_mb_y || mb_y == resync_mb_y+1 && mb_x < resync_mb_x || s->interlaced){
                 int toprow  = mb_y == resync_mb_y || mb_y == resync_mb_y+1 && mb_x < resync_mb_x;
                 int leftcol = !mb_x || mb_y == resync_mb_y && mb_x == resync_mb_x;

                 for (i = 0; i < nb_components; i++) {

                     uint8_t *ptr;

                     uint16_t *ptr16;

                     int n, h, v, x, y, c, j, linesize;
                     n = s->nb_blocks[i];
                     c = s->comp_index[i];
                     h = s->h_scount[i];
                     v = s->v_scount[i];
                     x = 0;
                     y = 0;
                     linesize= s->linesize[c];
 

                     if(bits>8) linesize /= 2;
 

                     for(j=0; j<n; j++) {

                         int pred, dc;

                         dc = mjpeg_decode_dc(s, s->dc_index[i]);
                         if(dc == 0xFFFF)
                             return -1;
                         if(bits<=8){

                         ptr = s->picture.data[c] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap

                         if(y==0 && toprow){
                             if(x==0 && leftcol){

                                 pred= 1 << (bits - 1);

                             }else{
                                 pred= ptr[-1];
                             }
                         }else{

                             if(x==0 && leftcol){

                                 pred= ptr[-linesize];
                             }else{
                                 PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                             }
                         }
 
                         if (s->interlaced && s->bottom_field)
                             ptr += linesize >> 1;

                         pred &= (-1)<<(8-s->bits);

                         *ptr= pred + (dc << point_transform);

                         }else{

                             ptr16 = (uint16_t*)(s->picture.data[c] + 2*(linesize * (v * mb_y + y)) + 2*(h * mb_x + x)); //FIXME optimize this crap

                             if(y==0 && toprow){
                                 if(x==0 && leftcol){

                                     pred= 1 << (bits - 1);
                                 }else{
                                     pred= ptr16[-1];
                                 }
                             }else{

                                 if(x==0 && leftcol){

                                     pred= ptr16[-linesize];
                                 }else{
                                     PREDICT(pred, ptr16[-linesize-1], ptr16[-linesize], ptr16[-1], predictor);
                                 }
                             }

                             if (s->interlaced && s->bottom_field)
                                 ptr16 += linesize >> 1;

                             pred &= (-1)<<(16-s->bits);

                             *ptr16= pred + (dc << point_transform);
                         }

                         if (++x == h) {
                             x = 0;
                             y++;
                         }
                     }
                 }

             } else {
                 for (i = 0; i < nb_components; i++) {

                     uint8_t *ptr;

                     uint16_t *ptr16;

                     int n, h, v, x, y, c, j, linesize, dc;

                     n        = s->nb_blocks[i];
                     c        = s->comp_index[i];
                     h        = s->h_scount[i];
                     v        = s->v_scount[i];
                     x        = 0;
                     y        = 0;
                     linesize = s->linesize[c];

                     if(bits>8) linesize /= 2;
 

                     for (j = 0; j < n; j++) {

                         int pred;
 

                         dc = mjpeg_decode_dc(s, s->dc_index[i]);
                         if(dc == 0xFFFF)
                             return -1;

                         if(bits<=8){

                             ptr = s->picture.data[c] +
                               (linesize * (v * mb_y + y)) +
                               (h * mb_x + x); //FIXME optimize this crap
                             PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);

                             pred &= (-1)<<(8-s->bits);
                             *ptr = pred + (dc << point_transform);

                         }else{

                             ptr16 = (uint16_t*)(s->picture.data[c] + 2*(linesize * (v * mb_y + y)) + 2*(h * mb_x + x)); //FIXME optimize this crap

                             PREDICT(pred, ptr16[-linesize-1], ptr16[-linesize], ptr16[-1], predictor);
 

                             pred &= (-1)<<(16-s->bits);

                             *ptr16= pred + (dc << point_transform);
                         }

                         if (++x == h) {
                             x = 0;
                             y++;
                         }
                     }
                 }
             }
             if (s->restart_interval && !--s->restart_count) {
                 align_get_bits(&s->gb);
                 skip_bits(&s->gb, 16); /* skip RSTn */
             }
         }
     }
     return 0;
 }
 

 static av_always_inline void mjpeg_copy_block(uint8_t *dst, const uint8_t *src,
                                               int linesize, int lowres)
 {
     switch (lowres) {
     case 0: copy_block8(dst, src, linesize, linesize, 8);
         break;
     case 1: copy_block4(dst, src, linesize, linesize, 4);
         break;
     case 2: copy_block2(dst, src, linesize, linesize, 2);
         break;
     case 3: *dst = *src;
         break;
     }
 }
 

 static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah,
                              int Al, const uint8_t *mb_bitmask,
                              const AVFrame *reference)
 {

     int i, mb_x, mb_y;

     uint8_t *data[MAX_COMPONENTS];

     const uint8_t *reference_data[MAX_COMPONENTS];

     int linesize[MAX_COMPONENTS];

     GetBitContext mb_bitmask_gb;
 

     if (mb_bitmask)
         init_get_bits(&mb_bitmask_gb, mb_bitmask, s->mb_width * s->mb_height);

     if (s->flipped && s->avctx->flags & CODEC_FLAG_EMU_EDGE) {
         av_log(s->avctx, AV_LOG_ERROR,
                "Can not flip image with CODEC_FLAG_EMU_EDGE set!\n");

         s->flipped = 0;
     }

     if (s->flipped && s->avctx->lowres) {
         av_log(s->avctx, AV_LOG_ERROR, "Can not flip image with lowres\n");
         s->flipped = 0;
     }

 
     for (i = 0; i < nb_components; i++) {
         int c   = s->comp_index[i];

         data[c] = s->picture_ptr->data[c];

         reference_data[c] = reference ? reference->data[c] : NULL;

         linesize[c] = s->linesize[c];

         s->coefs_finished[c] |= 1;

         if (s->flipped) {
             // picture should be flipped upside-down for this codec
             int offset = (linesize[c] * (s->v_scount[i] *
                          (8 * s->mb_height - ((s->height / s->v_max) & 7)) - 1));
             data[c]           += offset;

             reference_data[c] += offset;

             linesize[c]       *= -1;

         }

     }
 

     for (mb_y = 0; mb_y < s->mb_height; mb_y++) {
         for (mb_x = 0; mb_x < s->mb_width; mb_x++) {

             const int copy_mb = mb_bitmask && !get_bits1(&mb_bitmask_gb);
 

             if (s->restart_interval && !s->restart_count)
                 s->restart_count = s->restart_interval;
 

             if (get_bits_left(&s->gb) < 0) {

                 av_log(s->avctx, AV_LOG_ERROR, "overread %d\n",

                        -get_bits_left(&s->gb));

                 return -1;
             }

             for (i = 0; i < nb_components; i++) {

                 uint8_t *ptr;
                 int n, h, v, x, y, c, j;

                 int block_offset;

                 n = s->nb_blocks[i];
                 c = s->comp_index[i];
                 h = s->h_scount[i];
                 v = s->v_scount[i];
                 x = 0;
                 y = 0;

                 for (j = 0; j < n; j++) {

                     block_offset = (((linesize[c] * (v * mb_y + y) * 8) +
                                      (h * mb_x + x) * 8) >> s->avctx->lowres);

                     if (s->interlaced && s->bottom_field)

                         block_offset += linesize[c] >> 1;
                     ptr = data[c] + block_offset;

                     if (!s->progressive) {
                         if (copy_mb)

                             mjpeg_copy_block(ptr, reference_data[c] + block_offset,
                                              linesize[c], s->avctx->lowres);

                         else {
                             s->dsp.clear_block(s->block);
                             if (decode_block(s, s->block, i,
                                              s->dc_index[i], s->ac_index[i],
                                              s->quant_matrixes[s->quant_index[c]]) < 0) {
                                 av_log(s->avctx, AV_LOG_ERROR,
                                        "error y=%d x=%d\n", mb_y, mb_x);
                                 return -1;
                             }
                             s->dsp.idct_put(ptr, linesize[c], s->block);

                         }

                     } else {

                         int block_idx  = s->block_stride[c] * (v * mb_y + y) +
                                          (h * mb_x + x);

                         DCTELEM *block = s->blocks[c][block_idx];

                         if (Ah)
                             block[0] += get_bits1(&s->gb) *
                                         s->quant_matrixes[s->quant_index[c]][0] << Al;
                         else if (decode_dc_progressive(s, block, i, s->dc_index[i],
                                                        s->quant_matrixes[s->quant_index[c]],
                                                        Al) < 0) {
                             av_log(s->avctx, AV_LOG_ERROR,
                                    "error y=%d x=%d\n", mb_y, mb_x);

                             return -1;
                         }
                     }

                     // av_log(s->avctx, AV_LOG_DEBUG, "mb: %d %d processed\n",
                     //        mb_y, mb_x);
                     // av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d \n",
                     //        mb_x, mb_y, x, y, c, s->bottom_field,
                     //        (v * mb_y + y) * 8, (h * mb_x + x) * 8);

                     if (++x == h) {
                         x = 0;
                         y++;
                     }
                 }
             }

             if (s->restart_interval) {
                 s->restart_count--;

                 if(s->restart_count == 0 && s->avctx->codec_id == CODEC_ID_THP){
                     align_get_bits(&s->gb);
                     for (i = 0; i < nb_components; i++) /* reset dc */
                         s->last_dc[i] = 1024;
                 }
 

                 i = 8 + ((-get_bits_count(&s->gb)) & 7);
                 /* skip RSTn */
                 if (show_bits(&s->gb, i) == (1 << i) - 1) {
                     int pos = get_bits_count(&s->gb);
                     align_get_bits(&s->gb);
                     while (get_bits_left(&s->gb) >= 8 && show_bits(&s->gb, 8) == 0xFF)
                         skip_bits(&s->gb, 8);

                     if (get_bits_left(&s->gb) >= 8 && (get_bits(&s->gb, 8) & 0xF8) == 0xD0) {

                         for (i = 0; i < nb_components; i++) /* reset dc */
                             s->last_dc[i] = 1024;

                     } else

                         skip_bits_long(&s->gb, pos - get_bits_count(&s->gb));

                 }

             }
         }
     }
     return 0;
 }
 

 static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
                                             int se, int Ah, int Al)
 {

     int mb_x, mb_y;
     int EOBRUN = 0;
     int c = s->comp_index[0];

     uint8_t *data = s->picture.data[c];
     int linesize  = s->linesize[c];

     int last_scan = 0;

     int16_t *quant_matrix = s->quant_matrixes[s->quant_index[c]];

     if (!Al) {
         s->coefs_finished[c] |= (1LL << (se + 1)) - (1LL << ss);

         last_scan = !~s->coefs_finished[c];
     }
 

     if (s->interlaced && s->bottom_field)

         data += linesize >> 1;
 

     for (mb_y = 0; mb_y < s->mb_height; mb_y++) {
         uint8_t *ptr     = data + (mb_y * linesize * 8 >> s->avctx->lowres);
         int block_idx    = mb_y * s->block_stride[c];

         DCTELEM (*block)[64] = &s->blocks[c][block_idx];

         uint8_t *last_nnz    = &s->last_nnz[c][block_idx];
         for (mb_x = 0; mb_x < s->mb_width; mb_x++, block++, last_nnz++) {
                 int ret;
                 if (Ah)
                     ret = decode_block_refinement(s, *block, last_nnz, s->ac_index[0],
                                                   quant_matrix, ss, se, Al, &EOBRUN);
                 else
                     ret = decode_block_progressive(s, *block, last_nnz, s->ac_index[0],
                                                    quant_matrix, ss, se, Al, &EOBRUN);
                 if (ret < 0) {
                     av_log(s->avctx, AV_LOG_ERROR,
                            "error y=%d x=%d\n", mb_y, mb_x);
                     return -1;
                 }
 
             if (last_scan) {
                     s->dsp.idct_put(ptr, linesize, *block);
                     ptr += 8 >> s->avctx->lowres;

             }
         }
     }
     return 0;
 }
 

 int ff_mjpeg_decode_sos(MJpegDecodeContext *s, const uint8_t *mb_bitmask,
                         const AVFrame *reference)

 {
     int len, nb_components, i, h, v, predictor, point_transform;

     int index, id;

     const int block_size = s->lossless ? 1 : 8;

     int ilv, prev_shift;
 

     if (!s->got_picture) {
         av_log(s->avctx, AV_LOG_WARNING,
                 "Can not process SOS before SOF, skipping\n");
         return -1;
     }
 
     av_assert0(s->picture_ptr->data[0]);

     /* XXX: verify len field validity */
     len = get_bits(&s->gb, 16);
     nb_components = get_bits(&s->gb, 8);

     if (nb_components == 0 || nb_components > MAX_COMPONENTS) {
         av_log(s->avctx, AV_LOG_ERROR,
                "decode_sos: nb_components (%d) unsupported\n", nb_components);

         return -1;
     }

     if (len != 6 + 2 * nb_components) {

         av_log(s->avctx, AV_LOG_ERROR, "decode_sos: invalid len (%d)\n", len);
         return -1;
     }

     for (i = 0; i < nb_components; i++) {

         id = get_bits(&s->gb, 8) - 1;
         av_log(s->avctx, AV_LOG_DEBUG, "component: %d\n", id);
         /* find component index */

         for (index = 0; index < s->nb_components; index++)

             if (id == s->component_id[index])
                 break;

         if (index == s->nb_components) {
             av_log(s->avctx, AV_LOG_ERROR,
                    "decode_sos: index(%d) out of components\n", index);

             return -1;
         }

         /* Metasoft MJPEG codec has Cb and Cr swapped */
         if (s->avctx->codec_tag == MKTAG('M', 'T', 'S', 'J')
             && nb_components == 3 && s->nb_components == 3 && i)
             index = 3 - i;

         if(nb_components == 3 && s->nb_components == 3 && s->avctx->pix_fmt == PIX_FMT_GBR24P)
             index = (i+2)%3;

         if(nb_components == 1 && s->nb_components == 3 && s->avctx->pix_fmt == PIX_FMT_GBR24P)
             index = (index+2)%3;

         s->comp_index[i] = index;
 
         s->nb_blocks[i] = s->h_count[index] * s->v_count[index];

         s->h_scount[i]  = s->h_count[index];
         s->v_scount[i]  = s->v_count[index];

 
         s->dc_index[i] = get_bits(&s->gb, 4);
         s->ac_index[i] = get_bits(&s->gb, 4);
 
         if (s->dc_index[i] <  0 || s->ac_index[i] < 0 ||
             s->dc_index[i] >= 4 || s->ac_index[i] >= 4)
             goto out_of_range;

         if (!s->vlcs[0][s->dc_index[i]].table || !(s->progressive ? s->vlcs[2][s->ac_index[0]].table : s->vlcs[1][s->ac_index[i]].table))

             goto out_of_range;

     }
 

     predictor = get_bits(&s->gb, 8);       /* JPEG Ss / lossless JPEG predictor /JPEG-LS NEAR */
     ilv = get_bits(&s->gb, 8);             /* JPEG Se / JPEG-LS ILV */

     if(s->avctx->codec_tag != AV_RL32("CJPG")){

         prev_shift      = get_bits(&s->gb, 4); /* Ah */
         point_transform = get_bits(&s->gb, 4); /* Al */

     }else

         prev_shift = point_transform = 0;

     for (i = 0; i < nb_components; i++)

         s->last_dc[i] = 1024;
 
     if (nb_components > 1) {
         /* interleaved stream */
         s->mb_width  = (s->width  + s->h_max * block_size - 1) / (s->h_max * block_size);
         s->mb_height = (s->height + s->v_max * block_size - 1) / (s->v_max * block_size);

     } else if (!s->ls) { /* skip this for JPEG-LS */

         h = s->h_max / s->h_scount[0];
         v = s->v_max / s->v_scount[0];

         s->mb_width     = (s->width  + h * block_size - 1) / (h * block_size);
         s->mb_height    = (s->height + v * block_size - 1) / (v * block_size);

         s->nb_blocks[0] = 1;

         s->h_scount[0]  = 1;
         s->v_scount[0]  = 1;

     }
 

     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
         av_log(s->avctx, AV_LOG_DEBUG, "%s %s p:%d >>:%d ilv:%d bits:%d skip:%d %s comp:%d\n",
                s->lossless ? "lossless" : "sequential DCT", s->rgb ? "RGB" : "",

                predictor, point_transform, ilv, s->bits, s->mjpb_skiptosod,

                s->pegasus_rct ? "PRCT" : (s->rct ? "RCT" : ""), nb_components);

 
 
     /* mjpeg-b can have padding bytes between sos and image data, skip them */
     for (i = s->mjpb_skiptosod; i > 0; i--)
         skip_bits(&s->gb, 8);
 

     if (s->lossless) {

         av_assert0(s->picture_ptr == &s->picture);

         if (CONFIG_JPEGLS_DECODER && s->ls) {
 //            for () {

 //            reset_ls_coding_parameters(s, 0);
 

             if (ff_jpegls_decode_picture(s, predictor, point_transform, ilv) < 0)

                 return -1;

         } else {
             if (s->rgb) {
                 if (ljpeg_decode_rgb_scan(s, nb_components, predictor, point_transform) < 0)

                     return -1;

             } else {
                 if (ljpeg_decode_yuv_scan(s, predictor, point_transform) < 0)

                     return -1;
             }
         }

     } else {
         if (s->progressive && predictor) {

             av_assert0(s->picture_ptr == &s->picture);

             if (mjpeg_decode_scan_progressive_ac(s, predictor, ilv, prev_shift,
                                                  point_transform) < 0)

                 return -1;
         } else {

             if (mjpeg_decode_scan(s, nb_components, prev_shift, point_transform,
                                   mb_bitmask, reference) < 0)

                 return -1;
         }

     }
     emms_c();
     return 0;
  out_of_range:
     av_log(s->avctx, AV_LOG_ERROR, "decode_sos: ac/dc index out of range\n");
     return -1;
 }
 
 static int mjpeg_decode_dri(MJpegDecodeContext *s)
 {
     if (get_bits(&s->gb, 16) != 4)
         return -1;
     s->restart_interval = get_bits(&s->gb, 16);

     s->restart_count    = 0;
     av_log(s->avctx, AV_LOG_DEBUG, "restart interval: %d\n",
            s->restart_interval);

 
     return 0;
 }
 
 static int mjpeg_decode_app(MJpegDecodeContext *s)
 {
     int len, id, i;
 
     len = get_bits(&s->gb, 16);
     if (len < 5)
         return -1;

     if (8 * len > get_bits_left(&s->gb))

         return -1;
 

     id   = get_bits_long(&s->gb, 32);
     id   = av_be2ne32(id);

     len -= 6;
 

     if (s->avctx->debug & FF_DEBUG_STARTCODE)

         av_log(s->avctx, AV_LOG_DEBUG, "APPx %8X\n", id);
 

     /* Buggy AVID, it puts EOI only at every 10th frame. */
     /* Also, this fourcc is used by non-avid files too, it holds some
        information, but it's always present in AVID-created files. */

     if (id == AV_RL32("AVI1")) {

         /* structure:
             4bytes      AVI1
             1bytes      polarity
             1bytes      always zero
             4bytes      field_size
             4bytes      field_size_less_padding
         */
             s->buggy_avid = 1;
 //        if (s->first_picture)
 //            printf("mjpeg: workarounding buggy AVID\n");

         i = get_bits(&s->gb, 8); len--;

         av_log(s->avctx, AV_LOG_DEBUG, "polarity %d\n", i);

 #if 0
         skip_bits(&s->gb, 8);
         skip_bits(&s->gb, 32);
         skip_bits(&s->gb, 32);
         len -= 10;
 #endif
 //        if (s->interlace_polarity)
 //            printf("mjpeg: interlace polarity: %d\n", s->interlace_polarity);
         goto out;
     }
 
 //    len -= 2;
 

     if (id == AV_RL32("JFIF")) {

         int t_w, t_h, v1, v2;
         skip_bits(&s->gb, 8); /* the trailing zero-byte */

         v1 = get_bits(&s->gb, 8);
         v2 = get_bits(&s->gb, 8);

         skip_bits(&s->gb, 8);
 

         s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 16);
         s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 16);

 
         if (s->avctx->debug & FF_DEBUG_PICT_INFO)

             av_log(s->avctx, AV_LOG_INFO,
                    "mjpeg: JFIF header found (version: %x.%x) SAR=%d/%d\n",
                    v1, v2,
                    s->avctx->sample_aspect_ratio.num,
                    s->avctx->sample_aspect_ratio.den);

 
         t_w = get_bits(&s->gb, 8);
         t_h = get_bits(&s->gb, 8);

         if (t_w && t_h) {

             /* skip thumbnail */

             if (len -10 - (t_w * t_h * 3) > 0)
                 len -= t_w * t_h * 3;

         }
         len -= 10;
         goto out;
     }
 

     if (id == AV_RL32("Adob") && (get_bits(&s->gb, 8) == 'e')) {

         if (s->avctx->debug & FF_DEBUG_PICT_INFO)
             av_log(s->avctx, AV_LOG_INFO, "mjpeg: Adobe header found\n");
         skip_bits(&s->gb, 16); /* version */
         skip_bits(&s->gb, 16); /* flags0 */
         skip_bits(&s->gb, 16); /* flags1 */

         skip_bits(&s->gb,  8); /* transform */

         len -= 7;
         goto out;
     }
 

     if (id == AV_RL32("LJIF")) {

         if (s->avctx->debug & FF_DEBUG_PICT_INFO)

             av_log(s->avctx, AV_LOG_INFO,
                    "Pegasus lossless jpeg header found\n");

         skip_bits(&s->gb, 16); /* version ? */
         skip_bits(&s->gb, 16); /* unknwon always 0? */
         skip_bits(&s->gb, 16); /* unknwon always 0? */
         skip_bits(&s->gb, 16); /* unknwon always 0? */

         switch (get_bits(&s->gb, 8)) {

         case 1:

             s->rgb         = 1;
             s->pegasus_rct = 0;

             break;
         case 2:

             s->rgb         = 1;
             s->pegasus_rct = 1;

             break;
         default:
             av_log(s->avctx, AV_LOG_ERROR, "unknown colorspace\n");
         }
         len -= 9;
         goto out;
     }
 
     /* Apple MJPEG-A */

     if ((s->start_code == APP1) && (len > (0x28 - 8))) {
         id   = get_bits_long(&s->gb, 32);
         id   = av_be2ne32(id);

         len -= 4;

         /* Apple MJPEG-A */
         if (id == AV_RL32("mjpg")) {

 #if 0
             skip_bits(&s->gb, 32); /* field size */
             skip_bits(&s->gb, 32); /* pad field size */
             skip_bits(&s->gb, 32); /* next off */
             skip_bits(&s->gb, 32); /* quant off */
             skip_bits(&s->gb, 32); /* huff off */
             skip_bits(&s->gb, 32); /* image off */
             skip_bits(&s->gb, 32); /* scan off */
             skip_bits(&s->gb, 32); /* data off */
 #endif
             if (s->avctx->debug & FF_DEBUG_PICT_INFO)
                 av_log(s->avctx, AV_LOG_INFO, "mjpeg: Apple MJPEG-A header found\n");
         }
     }
 
 out:
     /* slow but needed for extreme adobe jpegs */
     if (len < 0)

         av_log(s->avctx, AV_LOG_ERROR,
                "mjpeg: error, decode_app parser read over the end\n");
     while (--len > 0)

         skip_bits(&s->gb, 8);
 
     return 0;
 }
 
 static int mjpeg_decode_com(MJpegDecodeContext *s)
 {
     int len = get_bits(&s->gb, 16);

     if (len >= 2 && 8 * len - 16 <= get_bits_left(&s->gb)) {

         char *cbuf = av_malloc(len - 1);
         if (cbuf) {
             int i;
             for (i = 0; i < len - 2; i++)
                 cbuf[i] = get_bits(&s->gb, 8);

             if (i > 0 && cbuf[i - 1] == '\n')
                 cbuf[i - 1] = 0;

             else
                 cbuf[i] = 0;
 

             if (s->avctx->debug & FF_DEBUG_PICT_INFO)

                 av_log(s->avctx, AV_LOG_INFO, "mjpeg comment: '%s'\n", cbuf);
 
             /* buggy avid, it puts EOI only at every 10th frame */

             if (!strcmp(cbuf, "AVID")) {

                 s->buggy_avid = 1;

                 // if (s->first_picture)
                 // printf("mjpeg: workarounding buggy AVID\n");
             } else if (!strcmp(cbuf, "CS=ITU601"))
                 s->cs_itu601 = 1;
             else if ((len > 20 && !strncmp(cbuf, "Intel(R) JPEG Library", 21)) ||
                      (len > 19 && !strncmp(cbuf, "Metasoft MJPEG Codec", 20)))

                 s->flipped = 1;

 
             av_free(cbuf);
         }
     }
 
     return 0;
 }
 
 /* return the 8 bit start code value and update the search
    state. Return -1 if no start code found */

 static int find_marker(const uint8_t **pbuf_ptr, const uint8_t *buf_end)

 {

     const uint8_t *buf_ptr;

     unsigned int v, v2;
     int val;

     int skipped = 0;

 
     buf_ptr = *pbuf_ptr;
     while (buf_ptr < buf_end) {

         v  = *buf_ptr++;

         v2 = *buf_ptr;
         if ((v == 0xff) && (v2 >= 0xc0) && (v2 <= 0xfe) && buf_ptr < buf_end) {
             val = *buf_ptr++;
             goto found;
         }
         skipped++;
     }
     val = -1;
 found:

     av_dlog(NULL, "find_marker skipped %d bytes\n", skipped);

     *pbuf_ptr = buf_ptr;
     return val;
 }
 

 int ff_mjpeg_find_marker(MJpegDecodeContext *s,
                          const uint8_t **buf_ptr, const uint8_t *buf_end,

                          const uint8_t **unescaped_buf_ptr,
                          int *unescaped_buf_size)

 {
     int start_code;

     start_code = find_marker(buf_ptr, buf_end);

     av_fast_padded_malloc(&s->buffer, &s->buffer_size, buf_end - *buf_ptr);
     if (!s->buffer)
         return AVERROR(ENOMEM);

     /* unescape buffer of SOS, use special treatment for JPEG-LS */
     if (start_code == SOS && !s->ls) {
         const uint8_t *src = *buf_ptr;
         uint8_t *dst = s->buffer;

         while (src < buf_end) {
             uint8_t x = *(src++);

             *(dst++) = x;
             if (s->avctx->codec_id != CODEC_ID_THP) {
                 if (x == 0xff) {
                     while (src < buf_end && x == 0xff)
                         x = *(src++);

                     if (x >= 0xd0 && x <= 0xd7)
                         *(dst++) = x;
                     else if (x)
                         break;

                 }

             }
         }
         *unescaped_buf_ptr  = s->buffer;
         *unescaped_buf_size = dst - s->buffer;
 
         av_log(s->avctx, AV_LOG_DEBUG, "escaping removed %td bytes\n",
                (buf_end - *buf_ptr) - (dst - s->buffer));
     } else if (start_code == SOS && s->ls) {
         const uint8_t *src = *buf_ptr;
         uint8_t *dst  = s->buffer;
         int bit_count = 0;
         int t = 0, b = 0;
         PutBitContext pb;
 
         s->cur_scan++;
 
         /* find marker */
         while (src + t < buf_end) {
             uint8_t x = src[t++];
             if (x == 0xff) {
                 while ((src + t < buf_end) && x == 0xff)
                     x = src[t++];
                 if (x & 0x80) {
                     t -= 2;
                     break;

                 }

             }
         }
         bit_count = t * 8;
         init_put_bits(&pb, dst, t);
 
         /* unescape bitstream */
         while (b < t) {
             uint8_t x = src[b++];
             put_bits(&pb, 8, x);
             if (x == 0xFF) {
                 x = src[b++];
                 put_bits(&pb, 7, x);
                 bit_count--;
             }
         }
         flush_put_bits(&pb);
 
         *unescaped_buf_ptr  = dst;
         *unescaped_buf_size = (bit_count + 7) >> 3;
     } else {
         *unescaped_buf_ptr  = *buf_ptr;
         *unescaped_buf_size = buf_end - *buf_ptr;
     }

 
     return start_code;
 }
 

 int ff_mjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                           AVPacket *avpkt)

 {
     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;

     MJpegDecodeContext *s = avctx->priv_data;
     const uint8_t *buf_end, *buf_ptr;
     const uint8_t *unescaped_buf_ptr;
     int unescaped_buf_size;
     int start_code;

     int i, index;

     AVFrame *picture = data;
 
     s->got_picture = 0; // picture from previous image can not be reused
     buf_ptr = buf;
     buf_end = buf + buf_size;
     while (buf_ptr < buf_end) {
         /* find start next marker */
         start_code = ff_mjpeg_find_marker(s, &buf_ptr, buf_end,

                                           &unescaped_buf_ptr,
                                           &unescaped_buf_size);
         /* EOF */
         if (start_code < 0) {
             goto the_end;

         } else if (unescaped_buf_size > (1U<<29)) {
             av_log(avctx, AV_LOG_ERROR, "MJPEG packet 0x%x too big (0x%x/0x%x), corrupt data?\n",

                    start_code, unescaped_buf_size, buf_size);

             return AVERROR_INVALIDDATA;

         } else {
             av_log(avctx, AV_LOG_DEBUG, "marker=%x avail_size_in_buf=%td\n",
                    start_code, buf_end - buf_ptr);
 
             init_get_bits(&s->gb, unescaped_buf_ptr, unescaped_buf_size * 8);
 
             s->start_code = start_code;
             if (s->avctx->debug & FF_DEBUG_STARTCODE)
                 av_log(avctx, AV_LOG_DEBUG, "startcode: %X\n", start_code);
 
             /* process markers */
             if (start_code >= 0xd0 && start_code <= 0xd7)
                 av_log(avctx, AV_LOG_DEBUG,
                        "restart marker: %d\n", start_code & 0x0f);
                 /* APP fields */
             else if (start_code >= APP0 && start_code <= APP15)
                 mjpeg_decode_app(s);
                 /* Comment */
             else if (start_code == COM)
                 mjpeg_decode_com(s);
 
             switch (start_code) {
             case SOI:
                 s->restart_interval = 0;
                 s->restart_count    = 0;
                 /* nothing to do on SOI */
                 break;
             case DQT:
                 ff_mjpeg_decode_dqt(s);
                 break;
             case DHT:
                 if (ff_mjpeg_decode_dht(s) < 0) {
                     av_log(avctx, AV_LOG_ERROR, "huffman table decode error\n");
                     return -1;

                 }

                 break;
             case SOF0:
             case SOF1:
                 s->lossless    = 0;
                 s->ls          = 0;
                 s->progressive = 0;
                 if (ff_mjpeg_decode_sof(s) < 0)
                     return -1;
                 break;
             case SOF2:
                 s->lossless    = 0;
                 s->ls          = 0;
                 s->progressive = 1;
                 if (ff_mjpeg_decode_sof(s) < 0)
                     return -1;
                 break;
             case SOF3:
                 s->lossless    = 1;
                 s->ls          = 0;
                 s->progressive = 0;
                 if (ff_mjpeg_decode_sof(s) < 0)
                     return -1;
                 break;
             case SOF48:
                 s->lossless    = 1;
                 s->ls          = 1;
                 s->progressive = 0;
                 if (ff_mjpeg_decode_sof(s) < 0)
                     return -1;
                 break;
             case LSE:
                 if (!CONFIG_JPEGLS_DECODER || ff_jpegls_decode_lse(s) < 0)
                     return -1;
                 break;
             case EOI:

 eoi_parser:

                 s->cur_scan = 0;
                 if (!s->got_picture) {
                     av_log(avctx, AV_LOG_WARNING,
                            "Found EOI before any SOF, ignoring\n");
                     break;
                 }
                 if (s->interlaced) {
                     s->bottom_field ^= 1;
                     /* if not bottom field, do not output image yet */
                     if (s->bottom_field == !s->interlace_polarity)

                         break;

                 }
                     *picture   = *s->picture_ptr;

                     *data_size = sizeof(AVFrame);
 

                     if (!s->lossless) {
                         picture->quality      = FFMAX3(s->qscale[0],
                                                        s->qscale[1],
                                                        s->qscale[2]);
                         picture->qstride      = 0;
                         picture->qscale_table = s->qscale_table;
                         memset(picture->qscale_table, picture->quality,
                                (s->width + 15) / 16);
                         if (avctx->debug & FF_DEBUG_QP)
                             av_log(avctx, AV_LOG_DEBUG,
                                    "QP: %d\n", picture->quality);
                         picture->quality *= FF_QP2LAMBDA;

                     }

                 goto the_end;
             case SOS:
                 if (ff_mjpeg_decode_sos(s, NULL, NULL) < 0 &&
                     (avctx->err_recognition & AV_EF_EXPLODE))
                     return AVERROR_INVALIDDATA;
                 break;
             case DRI:
                 mjpeg_decode_dri(s);
                 break;
             case SOF5:
             case SOF6:
             case SOF7:
             case SOF9:
             case SOF10:
             case SOF11:
             case SOF13:
             case SOF14:
             case SOF15:
             case JPG:
                 av_log(avctx, AV_LOG_ERROR,
                        "mjpeg: unsupported coding type (%x)\n", start_code);
                 break;
 //              default:
 //              printf("mjpeg: unsupported marker (%x)\n", start_code);
 //              break;

             }

 
             /* eof process start code */
             buf_ptr += (get_bits_count(&s->gb) + 7) / 8;
             av_log(avctx, AV_LOG_DEBUG,
                    "marker parser used %d bytes (%d bits)\n",
                    (get_bits_count(&s->gb) + 7) / 8, get_bits_count(&s->gb));

         }
     }

     if (s->got_picture) {
         av_log(avctx, AV_LOG_WARNING, "EOI missing, emulating\n");
         goto eoi_parser;
     }

     av_log(avctx, AV_LOG_FATAL, "No JPEG data found in image\n");
     return -1;

 the_end:

     if (s->upscale_h) {
         uint8_t *line = s->picture_ptr->data[s->upscale_h];
         av_assert0(avctx->pix_fmt == PIX_FMT_YUVJ444P ||
                    avctx->pix_fmt == PIX_FMT_YUV444P  ||
                    avctx->pix_fmt == PIX_FMT_YUVJ440P ||
                    avctx->pix_fmt == PIX_FMT_YUV440P);
         for (i = 0; i < s->chroma_height; i++) {
             for (index = s->width - 1; index; index--)
                 line[index] = (line[index / 2] + line[(index + 1) / 2]) >> 1;
             line += s->linesize[s->upscale_h];
         }
     }
     if (s->upscale_v) {
         uint8_t *dst = &((uint8_t *)s->picture_ptr->data[s->upscale_v])[(s->height - 1) * s->linesize[s->upscale_v]];
         av_assert0(avctx->pix_fmt == PIX_FMT_YUVJ444P ||
                    avctx->pix_fmt == PIX_FMT_YUV444P  ||
                    avctx->pix_fmt == PIX_FMT_YUVJ422P ||
                    avctx->pix_fmt == PIX_FMT_YUV422P);
         for (i = s->height - 1; i; i--) {
             uint8_t *src1 = &((uint8_t *)s->picture_ptr->data[s->upscale_v])[i / 2 * s->linesize[s->upscale_v]];
             uint8_t *src2 = &((uint8_t *)s->picture_ptr->data[s->upscale_v])[(i + 1) / 2 * s->linesize[s->upscale_v]];
             if (src1 == src2) {
                 memcpy(dst, src1, s->width);
             } else {
                 for (index = 0; index < s->width; index++)
                     dst[index] = (src1[index] + src2[index]) >> 1;
             }
             dst -= s->linesize[s->upscale_v];
         }
     }

     av_log(avctx, AV_LOG_DEBUG, "mjpeg decode frame unused %td bytes\n",
            buf_end - buf_ptr);
 //  return buf_end - buf_ptr;

     return buf_ptr - buf;
 }
 

 av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)

 {
     MJpegDecodeContext *s = avctx->priv_data;
     int i, j;
 

     if (s->picture_ptr && s->picture_ptr->data[0])
         avctx->release_buffer(avctx, s->picture_ptr);

     av_free(s->buffer);
     av_free(s->qscale_table);

     av_freep(&s->ljpeg_buffer);

     s->ljpeg_buffer_size = 0;

     for (i = 0; i < 3; i++) {
         for (j = 0; j < 4; j++)

             ff_free_vlc(&s->vlcs[i][j]);

     }

     for (i = 0; i < MAX_COMPONENTS; i++) {

         av_freep(&s->blocks[i]);
         av_freep(&s->last_nnz[i]);
     }

     return 0;
 }
 

 #define OFFSET(x) offsetof(MJpegDecodeContext, x)
 #define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
 static const AVOption options[] = {

     { "extern_huff", "Use external huffman table.",
       OFFSET(extern_huff), AV_OPT_TYPE_INT, { 0 }, 0, 1, VD },

     { NULL },
 };
 
 static const AVClass mjpegdec_class = {
     .class_name = "MJPEG decoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVCodec ff_mjpeg_decoder = {

     .name           = "mjpeg",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_MJPEG,
     .priv_data_size = sizeof(MJpegDecodeContext),
     .init           = ff_mjpeg_decode_init,
     .close          = ff_mjpeg_decode_end,
     .decode         = ff_mjpeg_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .max_lowres     = 3,

     .long_name      = NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),

     .priv_class     = &mjpegdec_class,

 };
 

 AVCodec ff_thp_decoder = {

     .name           = "thp",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_THP,
     .priv_data_size = sizeof(MJpegDecodeContext),
     .init           = ff_mjpeg_decode_init,
     .close          = ff_mjpeg_decode_end,
     .decode         = ff_mjpeg_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .max_lowres     = 3,

     .long_name      = NULL_IF_CONFIG_SMALL("Nintendo Gamecube THP video"),

 };