/*
  * Ut Video decoder
  * Copyright (c) 2011 Konstantin Shishkov
  *

  * 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
  * Ut Video decoder
  */
 

 #include <inttypes.h>

 #include <stdlib.h>
 
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"

 #include "bswapdsp.h"

 #include "bytestream.h"
 #include "get_bits.h"

 #include "thread.h"

 #include "utvideo.h"

 static int build_huff(const uint8_t *src, VLC *vlc, int *fsym)

 {
     int i;
     HuffEntry he[256];
     int last;
     uint32_t codes[256];
     uint8_t bits[256];
     uint8_t syms[256];
     uint32_t code;
 

     *fsym = -1;

     for (i = 0; i < 256; i++) {
         he[i].sym = i;
         he[i].len = *src++;
     }

     qsort(he, 256, sizeof(*he), ff_ut_huff_cmp_len);

     if (!he[0].len) {
         *fsym = he[0].sym;
         return 0;
     }

 
     last = 255;
     while (he[last].len == 255 && last)
         last--;
 

     if (he[last].len > 32)
         return -1;
 

     code = 1;
     for (i = last; i >= 0; i--) {
         codes[i] = code >> (32 - he[i].len);
         bits[i]  = he[i].len;
         syms[i]  = he[i].sym;
         code += 0x80000000u >> (he[i].len - 1);
     }
 

     return ff_init_vlc_sparse(vlc, FFMIN(he[last].len, 11), last + 1,

                               bits,  sizeof(*bits),  sizeof(*bits),
                               codes, sizeof(*codes), sizeof(*codes),
                               syms,  sizeof(*syms),  sizeof(*syms), 0);

 }
 
 static int decode_plane(UtvideoContext *c, int plane_no,
                         uint8_t *dst, int step, int stride,
                         int width, int height,

                         const uint8_t *src, int use_pred)

 {
     int i, j, slice, pix;
     int sstart, send;
     VLC vlc;
     GetBitContext gb;

     int prev, fsym;

     const int cmask = ~(!plane_no && c->avctx->pix_fmt == AV_PIX_FMT_YUV420P);

     if (build_huff(src, &vlc, &fsym)) {

         av_log(c->avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n");
         return AVERROR_INVALIDDATA;
     }

     if (fsym >= 0) { // build_huff reported a symbol to fill slices with
         send = 0;
         for (slice = 0; slice < c->slices; slice++) {
             uint8_t *dest;
 
             sstart = send;
             send   = (height * (slice + 1) / c->slices) & cmask;
             dest   = dst + sstart * stride;
 
             prev = 0x80;
             for (j = sstart; j < send; j++) {
                 for (i = 0; i < width * step; i += step) {
                     pix = fsym;
                     if (use_pred) {
                         prev += pix;
                         pix   = prev;
                     }
                     dest[i] = pix;
                 }
                 dest += stride;
             }
         }
         return 0;
     }

 
     src      += 256;
 
     send = 0;
     for (slice = 0; slice < c->slices; slice++) {
         uint8_t *dest;
         int slice_data_start, slice_data_end, slice_size;
 
         sstart = send;

         send   = (height * (slice + 1) / c->slices) & cmask;

         dest   = dst + sstart * stride;
 
         // slice offset and size validation was done earlier
         slice_data_start = slice ? AV_RL32(src + slice * 4 - 4) : 0;
         slice_data_end   = AV_RL32(src + slice * 4);
         slice_size       = slice_data_end - slice_data_start;
 
         if (!slice_size) {

             av_log(c->avctx, AV_LOG_ERROR, "Plane has more than one symbol "
                    "yet a slice has a length of zero.\n");
             goto fail;

         }
 

         memcpy(c->slice_bits, src + slice_data_start + c->slices * 4,
                slice_size);

         memset(c->slice_bits + slice_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);

         c->bdsp.bswap_buf((uint32_t *) c->slice_bits,
                           (uint32_t *) c->slice_bits,
                           (slice_data_end - slice_data_start + 3) >> 2);

         init_get_bits(&gb, c->slice_bits, slice_size * 8);
 
         prev = 0x80;
         for (j = sstart; j < send; j++) {
             for (i = 0; i < width * step; i += step) {
                 if (get_bits_left(&gb) <= 0) {

                     av_log(c->avctx, AV_LOG_ERROR,
                            "Slice decoding ran out of bits\n");

                     goto fail;
                 }

                 pix = get_vlc2(&gb, vlc.table, vlc.bits, 3);

                 if (pix < 0) {
                     av_log(c->avctx, AV_LOG_ERROR, "Decoding error\n");
                     goto fail;
                 }
                 if (use_pred) {
                     prev += pix;
                     pix   = prev;
                 }
                 dest[i] = pix;
             }
             dest += stride;
         }
         if (get_bits_left(&gb) > 32)

             av_log(c->avctx, AV_LOG_WARNING,
                    "%d bits left after decoding slice\n", get_bits_left(&gb));

     }
 

     ff_free_vlc(&vlc);

 
     return 0;
 fail:

     ff_free_vlc(&vlc);

     return AVERROR_INVALIDDATA;
 }
 

 static void restore_rgb_planes(uint8_t *src, int step, int stride, int width,
                                int height)

 {
     int i, j;
     uint8_t r, g, b;
 
     for (j = 0; j < height; j++) {
         for (i = 0; i < width * step; i += step) {
             r = src[i];
             g = src[i + 1];
             b = src[i + 2];
             src[i]     = r + g - 0x80;
             src[i + 2] = b + g - 0x80;
         }
         src += stride;
     }
 }
 
 static void restore_median(uint8_t *src, int step, int stride,

                            int width, int height, int slices, int rmode)

 {
     int i, j, slice;
     int A, B, C;
     uint8_t *bsrc;
     int slice_start, slice_height;

     const int cmask = ~rmode;

 
     for (slice = 0; slice < slices; slice++) {

         slice_start  = ((slice * height) / slices) & cmask;
         slice_height = ((((slice + 1) * height) / slices) & cmask) -
                        slice_start;

 
         bsrc = src + slice_start * stride;
 
         // first line - left neighbour prediction
         bsrc[0] += 0x80;
         A = bsrc[0];
         for (i = step; i < width * step; i += step) {
             bsrc[i] += A;

             A        = bsrc[i];

         }
         bsrc += stride;

         if (slice_height <= 1)

             continue;

         // second line - first element has top prediction, the rest uses median
         C        = bsrc[-stride];

         bsrc[0] += C;

         A        = bsrc[0];

         for (i = step; i < width * step; i += step) {

             B        = bsrc[i - stride];

             bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));

             C        = B;
             A        = bsrc[i];

         }
         bsrc += stride;
         // the rest of lines use continuous median prediction
         for (j = 2; j < slice_height; j++) {
             for (i = 0; i < width * step; i += step) {

                 B        = bsrc[i - stride];

                 bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));

                 C        = B;
                 A        = bsrc[i];

             }
             bsrc += stride;
         }
     }
 }
 

 /* UtVideo interlaced mode treats every two lines as a single one,
  * so restoring function should take care of possible padding between
  * two parts of the same "line".
  */
 static void restore_median_il(uint8_t *src, int step, int stride,
                               int width, int height, int slices, int rmode)
 {
     int i, j, slice;
     int A, B, C;
     uint8_t *bsrc;
     int slice_start, slice_height;

     const int cmask   = ~(rmode ? 3 : 1);

     const int stride2 = stride << 1;
 
     for (slice = 0; slice < slices; slice++) {
         slice_start    = ((slice * height) / slices) & cmask;

         slice_height   = ((((slice + 1) * height) / slices) & cmask) -
                          slice_start;

         slice_height >>= 1;
 
         bsrc = src + slice_start * stride;
 
         // first line - left neighbour prediction
         bsrc[0] += 0x80;

         A        = bsrc[0];

         for (i = step; i < width * step; i += step) {
             bsrc[i] += A;

             A        = bsrc[i];

         }
         for (i = 0; i < width * step; i += step) {
             bsrc[stride + i] += A;

             A                 = bsrc[stride + i];

         }
         bsrc += stride2;

         if (slice_height <= 1)

             continue;

         // second line - first element has top prediction, the rest uses median
         C        = bsrc[-stride2];

         bsrc[0] += C;

         A        = bsrc[0];

         for (i = step; i < width * step; i += step) {

             B        = bsrc[i - stride2];

             bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));

             C        = B;
             A        = bsrc[i];

         }
         for (i = 0; i < width * step; i += step) {

             B                 = bsrc[i - stride];

             bsrc[stride + i] += mid_pred(A, B, (uint8_t)(A + B - C));

             C                 = B;
             A                 = bsrc[stride + i];

         }
         bsrc += stride2;
         // the rest of lines use continuous median prediction
         for (j = 2; j < slice_height; j++) {
             for (i = 0; i < width * step; i += step) {

                 B        = bsrc[i - stride2];

                 bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));

                 C        = B;
                 A        = bsrc[i];

             }
             for (i = 0; i < width * step; i += step) {

                 B                 = bsrc[i - stride];

                 bsrc[i + stride] += mid_pred(A, B, (uint8_t)(A + B - C));

                 C                 = B;
                 A                 = bsrc[i + stride];

             }
             bsrc += stride2;
         }
     }
 }
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

                         AVPacket *avpkt)

 {
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     UtvideoContext *c = avctx->priv_data;
     int i, j;
     const uint8_t *plane_start[5];
     int plane_size, max_slice_size = 0, slice_start, slice_end, slice_size;
     int ret;

     GetByteContext gb;

     ThreadFrame frame = { .f = data };

     if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)

         return ret;
 

     /* parse plane structure to get frame flags and validate slice offsets */

     bytestream2_init(&gb, buf, buf_size);

     for (i = 0; i < c->planes; i++) {

         plane_start[i] = gb.buffer;
         if (bytestream2_get_bytes_left(&gb) < 256 + 4 * c->slices) {

             av_log(avctx, AV_LOG_ERROR, "Insufficient data for a plane\n");
             return AVERROR_INVALIDDATA;
         }

         bytestream2_skipu(&gb, 256);

         slice_start = 0;
         slice_end   = 0;
         for (j = 0; j < c->slices; j++) {

             slice_end   = bytestream2_get_le32u(&gb);

             slice_size  = slice_end - slice_start;

             if (slice_end < 0 || slice_size < 0 ||

                 bytestream2_get_bytes_left(&gb) < slice_end) {

                 av_log(avctx, AV_LOG_ERROR, "Incorrect slice size\n");
                 return AVERROR_INVALIDDATA;
             }
             slice_start = slice_end;
             max_slice_size = FFMAX(max_slice_size, slice_size);
         }
         plane_size = slice_end;

         bytestream2_skipu(&gb, plane_size);

     }

     plane_start[c->planes] = gb.buffer;
     if (bytestream2_get_bytes_left(&gb) < c->frame_info_size) {

         av_log(avctx, AV_LOG_ERROR, "Not enough data for frame information\n");
         return AVERROR_INVALIDDATA;
     }

     c->frame_info = bytestream2_get_le32u(&gb);

     av_log(avctx, AV_LOG_DEBUG, "frame information flags %"PRIX32"\n",
            c->frame_info);

 
     c->frame_pred = (c->frame_info >> 8) & 3;
 
     if (c->frame_pred == PRED_GRADIENT) {

         avpriv_request_sample(avctx, "Frame with gradient prediction");

         return AVERROR_PATCHWELCOME;
     }
 
     av_fast_malloc(&c->slice_bits, &c->slice_bits_size,
                    max_slice_size + FF_INPUT_BUFFER_PADDING_SIZE);
 
     if (!c->slice_bits) {
         av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
         return AVERROR(ENOMEM);
     }
 
     switch (c->avctx->pix_fmt) {

     case AV_PIX_FMT_RGB24:
     case AV_PIX_FMT_RGBA:

         for (i = 0; i < c->planes; i++) {

             ret = decode_plane(c, i, frame.f->data[0] + ff_ut_rgb_order[i],
                                c->planes, frame.f->linesize[0], avctx->width,

                                avctx->height, plane_start[i],
                                c->frame_pred == PRED_LEFT);

             if (ret)
                 return ret;

             if (c->frame_pred == PRED_MEDIAN) {

                 if (!c->interlaced) {

                     restore_median(frame.f->data[0] + ff_ut_rgb_order[i],
                                    c->planes, frame.f->linesize[0], avctx->width,

                                    avctx->height, c->slices, 0);

                 } else {

                     restore_median_il(frame.f->data[0] + ff_ut_rgb_order[i],
                                       c->planes, frame.f->linesize[0],

                                       avctx->width, avctx->height, c->slices,
                                       0);

                 }

             }

         }

         restore_rgb_planes(frame.f->data[0], c->planes, frame.f->linesize[0],

                            avctx->width, avctx->height);
         break;

     case AV_PIX_FMT_YUV420P:

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

             ret = decode_plane(c, i, frame.f->data[i], 1, frame.f->linesize[i],

                                avctx->width >> !!i, avctx->height >> !!i,

                                plane_start[i], c->frame_pred == PRED_LEFT);

             if (ret)
                 return ret;

             if (c->frame_pred == PRED_MEDIAN) {
                 if (!c->interlaced) {

                     restore_median(frame.f->data[i], 1, frame.f->linesize[i],

                                    avctx->width >> !!i, avctx->height >> !!i,
                                    c->slices, !i);
                 } else {

                     restore_median_il(frame.f->data[i], 1, frame.f->linesize[i],

                                       avctx->width  >> !!i,
                                       avctx->height >> !!i,
                                       c->slices, !i);
                 }
             }

         }
         break;

     case AV_PIX_FMT_YUV422P:

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

             ret = decode_plane(c, i, frame.f->data[i], 1, frame.f->linesize[i],

                                avctx->width >> !!i, avctx->height,

                                plane_start[i], c->frame_pred == PRED_LEFT);

             if (ret)
                 return ret;

             if (c->frame_pred == PRED_MEDIAN) {
                 if (!c->interlaced) {

                     restore_median(frame.f->data[i], 1, frame.f->linesize[i],

                                    avctx->width >> !!i, avctx->height,
                                    c->slices, 0);
                 } else {

                     restore_median_il(frame.f->data[i], 1, frame.f->linesize[i],

                                       avctx->width >> !!i, avctx->height,
                                       c->slices, 0);
                 }
             }

         }
         break;
     }
 

     frame.f->key_frame = 1;
     frame.f->pict_type = AV_PICTURE_TYPE_I;
     frame.f->interlaced_frame = !!c->interlaced;

     *got_frame = 1;

 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     UtvideoContext * const c = avctx->priv_data;
 
     c->avctx = avctx;
 

     ff_bswapdsp_init(&c->bdsp);

 
     if (avctx->extradata_size < 16) {

         av_log(avctx, AV_LOG_ERROR,
                "Insufficient extradata size %d, should be at least 16\n",

                avctx->extradata_size);
         return AVERROR_INVALIDDATA;
     }
 
     av_log(avctx, AV_LOG_DEBUG, "Encoder version %d.%d.%d.%d\n",
            avctx->extradata[3], avctx->extradata[2],
            avctx->extradata[1], avctx->extradata[0]);

     av_log(avctx, AV_LOG_DEBUG, "Original format %"PRIX32"\n",

            AV_RB32(avctx->extradata + 4));

     c->frame_info_size = AV_RL32(avctx->extradata + 8);
     c->flags           = AV_RL32(avctx->extradata + 12);
 
     if (c->frame_info_size != 4)

         avpriv_request_sample(avctx, "Frame info not 4 bytes");

     av_log(avctx, AV_LOG_DEBUG, "Encoding parameters %08"PRIX32"\n", c->flags);

     c->slices      = (c->flags >> 24) + 1;
     c->compression = c->flags & 1;
     c->interlaced  = c->flags & 0x800;
 
     c->slice_bits_size = 0;
 
     switch (avctx->codec_tag) {
     case MKTAG('U', 'L', 'R', 'G'):
         c->planes      = 3;

         avctx->pix_fmt = AV_PIX_FMT_RGB24;

         break;
     case MKTAG('U', 'L', 'R', 'A'):
         c->planes      = 4;

         avctx->pix_fmt = AV_PIX_FMT_RGBA;

         break;
     case MKTAG('U', 'L', 'Y', '0'):
         c->planes      = 3;

         avctx->pix_fmt = AV_PIX_FMT_YUV420P;

         avctx->colorspace = AVCOL_SPC_BT470BG;

         break;
     case MKTAG('U', 'L', 'Y', '2'):
         c->planes      = 3;

         avctx->pix_fmt = AV_PIX_FMT_YUV422P;

         avctx->colorspace = AVCOL_SPC_BT470BG;

         break;

     case MKTAG('U', 'L', 'H', '0'):
         c->planes      = 3;

         avctx->pix_fmt = AV_PIX_FMT_YUV420P;

         avctx->colorspace = AVCOL_SPC_BT709;
         break;
     case MKTAG('U', 'L', 'H', '2'):
         c->planes      = 3;

         avctx->pix_fmt = AV_PIX_FMT_YUV422P;

         avctx->colorspace = AVCOL_SPC_BT709;
         break;

     default:
         av_log(avctx, AV_LOG_ERROR, "Unknown Ut Video FOURCC provided (%08X)\n",
                avctx->codec_tag);
         return AVERROR_INVALIDDATA;
     }
 
     return 0;
 }
 
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     UtvideoContext * const c = avctx->priv_data;
 
     av_freep(&c->slice_bits);
 
     return 0;
 }
 
 AVCodec ff_utvideo_decoder = {
     .name           = "utvideo",

     .long_name      = NULL_IF_CONFIG_SMALL("Ut Video"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_UTVIDEO,

     .priv_data_size = sizeof(UtvideoContext),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_frame,

     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,

 };