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

 
     assert(nb_codes <= 256);
 
     memset(huff_size, 0, sizeof(huff_size));

     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 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;
     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 FF_API_MJPEG_GLOBAL_OPTS

     if (avctx->flags & CODEC_FLAG_EXTERN_HUFF)

         s->extern_huff = 1;
 #endif
     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->extradata_size > 9 &&
         AV_RL32(avctx->extradata + 4) == MKTAG('f','i','e','l')) {
         if (avctx->extradata[9] == 6) { /* 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 */
         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){
             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;
 

     /* 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->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];
         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))
         return 0;
 
     /* 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 0x11000000:

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

         break;

     case 0x12111100:

         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;

         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 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->ls){
         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;
 

     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++) {
         const int modified_predictor= mb_y ? predictor : 1;
         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++) {
             if (s->restart_interval && !s->restart_count)
                 s->restart_count = s->restart_interval;
 

             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;
 
     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;
 
             if(mb_x==0 || mb_y==0 || s->interlaced){
                 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 && mb_y==0){
                             if(x==0 && mb_x==0){

                                 pred= 1 << (bits - 1);

                             }else{
                                 pred= ptr[-1];
                             }
                         }else{
                             if(x==0 && mb_x==0){
                                 pred= ptr[-linesize];
                             }else{
                                 PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                             }
                         }
 
                         if (s->interlaced && s->bottom_field)
                             ptr += linesize >> 1;

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

                         }else{
                             ptr16 = s->picture.data[c] + 2*(linesize * (v * mb_y + y)) + 2*(h * mb_x + x); //FIXME optimize this crap
                             if(y==0 && mb_y==0){
                                 if(x==0 && mb_x==0){
                                     pred= 1 << (bits - 1);
                                 }else{
                                     pred= ptr16[-1];
                                 }
                             }else{
                                 if(x==0 && mb_x==0){
                                     pred= ptr16[-linesize];
                                 }else{
                                     PREDICT(pred, ptr16[-linesize-1], ptr16[-linesize], ptr16[-1], predictor);
                                 }
                             }

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

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

                         }else{
                             ptr16 = 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);
 
                             *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;
     }

     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_count(&s->gb)>s->gb.size_in_bits){
                 av_log(s->avctx, AV_LOG_ERROR, "overread %d\n", get_bits_count(&s->gb) - s->gb.size_in_bits);
                 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;

             i= 8+((-get_bits_count(&s->gb))&7);
             if (s->restart_interval && show_bits(&s->gb, i)  == (1<<i)-1){ /* skip RSTn */

                 int pos= get_bits_count(&s->gb);

                 align_get_bits(&s->gb);

                 while(get_bits_count(&s->gb) < s->gb.size_in_bits && show_bits(&s->gb, 8) == 0xFF)

                     skip_bits(&s->gb, 8);

                 if(get_bits_count(&s->gb) < s->gb.size_in_bits && (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;
 
     /* 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;
 

         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_count(&s->gb) > s->gb.size_in_bits)
         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
        informations, but it's always present in AVID creates 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;

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

         {
 #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_count(&s->gb) <= s->gb.size_in_bits) {
         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);

                 if ((buf_end - *buf_ptr) > s->buffer_size)

                 {
                     av_free(s->buffer);

                     s->buffer_size = buf_end - *buf_ptr;

                     s->buffer = av_malloc(s->buffer_size + FF_INPUT_BUFFER_PADDING_SIZE);

                     av_log(s->avctx, AV_LOG_DEBUG, "buffer too small, expanding to %d bytes\n",

                         s->buffer_size);
                 }
 
                 /* 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;
     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 {
                 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 (!s->got_picture) {
                         av_log(avctx, AV_LOG_WARNING, "Can not process SOS before SOF, skipping\n");
                         break;
                     }

                     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:

     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++)
             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"),

 };