/*
  * Dxtory 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
  */
 

 #include <inttypes.h>
 

 #define BITSTREAM_READER_LE

 #include "avcodec.h"

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

 #include "internal.h"

 #include "unary.h"

 #include "libavutil/common.h"

 #include "libavutil/intreadwrite.h"
 

 static int dxtory_decode_v1_rgb(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size,
                                 int id, int bpp)
 {
     int h;
     uint8_t *dst;
     int ret;
 

     if (src_size < avctx->width * avctx->height * (int64_t)bpp) {

         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     avctx->pix_fmt = id;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     dst = pic->data[0];
     for (h = 0; h < avctx->height; h++) {
         memcpy(dst, src, avctx->width * bpp);
         src += avctx->width * bpp;
         dst += pic->linesize[0];
     }
 
     return 0;
 }
 
 static int dxtory_decode_v1_410(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
     int h, w;
     uint8_t *Y1, *Y2, *Y3, *Y4, *U, *V;
     int ret;
 

     if (src_size < avctx->width * avctx->height * 9L / 8) {

         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     Y1 = pic->data[0];
     Y2 = pic->data[0] + pic->linesize[0];
     Y3 = pic->data[0] + pic->linesize[0] * 2;
     Y4 = pic->data[0] + pic->linesize[0] * 3;
     U  = pic->data[1];
     V  = pic->data[2];
     for (h = 0; h < avctx->height; h += 4) {
         for (w = 0; w < avctx->width; w += 4) {
             AV_COPY32(Y1 + w, src);
             AV_COPY32(Y2 + w, src + 4);
             AV_COPY32(Y3 + w, src + 8);
             AV_COPY32(Y4 + w, src + 12);
             U[w >> 2] = src[16] + 0x80;
             V[w >> 2] = src[17] + 0x80;
             src += 18;
         }
         Y1 += pic->linesize[0] << 2;
         Y2 += pic->linesize[0] << 2;
         Y3 += pic->linesize[0] << 2;
         Y4 += pic->linesize[0] << 2;
         U  += pic->linesize[1];
         V  += pic->linesize[2];
     }
 
     return 0;
 }
 
 static int dxtory_decode_v1_420(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)

 {
     int h, w;
     uint8_t *Y1, *Y2, *U, *V;
     int ret;
 

     if (src_size < avctx->width * avctx->height * 3L / 2) {

         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_YUV420P;

     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

         return ret;
 
     Y1 = pic->data[0];
     Y2 = pic->data[0] + pic->linesize[0];
     U  = pic->data[1];
     V  = pic->data[2];
     for (h = 0; h < avctx->height; h += 2) {
         for (w = 0; w < avctx->width; w += 2) {

             AV_COPY16(Y1 + w, src);
             AV_COPY16(Y2 + w, src + 2);

             U[w >> 1] = src[4] + 0x80;
             V[w >> 1] = src[5] + 0x80;
             src += 6;
         }
         Y1 += pic->linesize[0] << 1;
         Y2 += pic->linesize[0] << 1;
         U  += pic->linesize[1];
         V  += pic->linesize[2];
     }
 

     return 0;
 }
 

 static int dxtory_decode_v1_444(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
     int h, w;
     uint8_t *Y, *U, *V;
     int ret;
 

     if (src_size < avctx->width * avctx->height * 3L) {

         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     avctx->pix_fmt = AV_PIX_FMT_YUV444P;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     Y = pic->data[0];
     U = pic->data[1];
     V = pic->data[2];
     for (h = 0; h < avctx->height; h++) {
         for (w = 0; w < avctx->width; w++) {
             Y[w] = *src++;
             U[w] = *src++ ^ 0x80;
             V[w] = *src++ ^ 0x80;
         }
         Y += pic->linesize[0];
         U += pic->linesize[1];
         V += pic->linesize[2];
     }
 
     return 0;
 }
 

 static const uint8_t def_lru[8] = { 0x00, 0x20, 0x40, 0x60, 0x80, 0xA0, 0xC0, 0xFF };

 static const uint8_t def_lru_555[8] = { 0x00, 0x08, 0x10, 0x18, 0x1F };
 static const uint8_t def_lru_565[8] = { 0x00, 0x08, 0x10, 0x20, 0x30, 0x3F };

 
 static inline uint8_t decode_sym(GetBitContext *gb, uint8_t lru[8])
 {
     uint8_t c, val;
 
     c = get_unary(gb, 0, 8);
     if (!c) {
         val = get_bits(gb, 8);
         memmove(lru + 1, lru, sizeof(*lru) * (8 - 1));
     } else {
         val = lru[c - 1];
         memmove(lru + 1, lru, sizeof(*lru) * (c - 1));
     }
     lru[0] = val;
 
     return val;
 }
 

 static inline uint8_t decode_sym_565(GetBitContext *gb, uint8_t lru[8],
                                      int bits)
 {
     uint8_t c, val;
 
     c = get_unary(gb, 0, bits);
     if (!c) {
         val = get_bits(gb, bits);
         memmove(lru + 1, lru, sizeof(*lru) * (6 - 1));
     } else {
         val = lru[c - 1];
         memmove(lru + 1, lru, sizeof(*lru) * (c - 1));
     }
     lru[0] = val;
 
     return val;
 }
 
 static int dx2_decode_slice_565(GetBitContext *gb, int width, int height,
                                 uint8_t *dst, int stride, int is_565)
 {
     int x, y;
     int r, g, b;
     uint8_t lru[3][8];
 
     memcpy(lru[0], def_lru_555, 8 * sizeof(*def_lru));
     memcpy(lru[1], is_565 ? def_lru_565 : def_lru_555, 8 * sizeof(*def_lru));
     memcpy(lru[2], def_lru_555, 8 * sizeof(*def_lru));
 
     for (y = 0; y < height; y++) {
         for (x = 0; x < width; x++) {
             b = decode_sym_565(gb, lru[0], 5);
             g = decode_sym_565(gb, lru[1], is_565 ? 6 : 5);
             r = decode_sym_565(gb, lru[2], 5);
             dst[x * 3 + 0] = (r << 3) | (r >> 2);
             dst[x * 3 + 1] = is_565 ? (g << 2) | (g >> 4) : (g << 3) | (g >> 2);
             dst[x * 3 + 2] = (b << 3) | (b >> 2);
         }
 
         dst += stride;
     }
 
     return 0;
 }
 
 static int dxtory_decode_v2_565(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size, int is_565)
 {
     GetByteContext gb;
     GetBitContext  gb2;
     int nslices, slice, slice_height;
     uint32_t off, slice_size;
     uint8_t *dst;
     int ret;
 
     bytestream2_init(&gb, src, src_size);
     nslices = bytestream2_get_le16(&gb);
     off = FFALIGN(nslices * 4 + 2, 16);
     if (src_size < off) {
         av_log(avctx, AV_LOG_ERROR, "no slice data\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!nslices || avctx->height % nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,
                               avctx->width, avctx->height);
         return AVERROR_PATCHWELCOME;
     }
 
     slice_height = avctx->height / nslices;
     avctx->pix_fmt = AV_PIX_FMT_RGB24;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     dst = pic->data[0];
     for (slice = 0; slice < nslices; slice++) {
         slice_size = bytestream2_get_le32(&gb);
         if (slice_size > src_size - off) {
             av_log(avctx, AV_LOG_ERROR,

                    "invalid slice size %"PRIu32" (only %"PRIu32" bytes left)\n",

                    slice_size, src_size - off);
             return AVERROR_INVALIDDATA;
         }
         if (slice_size <= 16) {

             av_log(avctx, AV_LOG_ERROR, "invalid slice size %"PRIu32"\n", slice_size);

             return AVERROR_INVALIDDATA;
         }
 
         if (AV_RL32(src + off) != slice_size - 16) {
             av_log(avctx, AV_LOG_ERROR,

                    "Slice sizes mismatch: got %"PRIu32" instead of %"PRIu32"\n",

                    AV_RL32(src + off), slice_size - 16);
         }
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
         dx2_decode_slice_565(&gb2, avctx->width, slice_height, dst,
                              pic->linesize[0], is_565);
 
         dst += pic->linesize[0] * slice_height;
         off += slice_size;
     }
 
     return 0;
 }
 

 static int dx2_decode_slice_rgb(GetBitContext *gb, int width, int height,
                                 uint8_t *dst, int stride)
 {
     int x, y, i;
     uint8_t lru[3][8];
 
     for (i = 0; i < 3; i++)
         memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
 
     for (y = 0; y < height; y++) {
         for (x = 0; x < width; x++) {
             dst[x * 3 + 0] = decode_sym(gb, lru[0]);
             dst[x * 3 + 1] = decode_sym(gb, lru[1]);
             dst[x * 3 + 2] = decode_sym(gb, lru[2]);
         }
 
         dst += stride;
     }
 
     return 0;
 }
 
 static int dxtory_decode_v2_rgb(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
     GetByteContext gb;
     GetBitContext  gb2;
     int nslices, slice, slice_height;
     uint32_t off, slice_size;
     uint8_t *dst;
     int ret;
 
     bytestream2_init(&gb, src, src_size);
     nslices = bytestream2_get_le16(&gb);
     off = FFALIGN(nslices * 4 + 2, 16);
     if (src_size < off) {
         av_log(avctx, AV_LOG_ERROR, "no slice data\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!nslices || avctx->height % nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,
                               avctx->width, avctx->height);
         return AVERROR_PATCHWELCOME;
     }
 
     slice_height = avctx->height / nslices;
     avctx->pix_fmt = AV_PIX_FMT_BGR24;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     dst = pic->data[0];
     for (slice = 0; slice < nslices; slice++) {
         slice_size = bytestream2_get_le32(&gb);
         if (slice_size > src_size - off) {
             av_log(avctx, AV_LOG_ERROR,

                    "invalid slice size %"PRIu32" (only %"PRIu32" bytes left)\n",

                    slice_size, src_size - off);
             return AVERROR_INVALIDDATA;
         }
         if (slice_size <= 16) {

             av_log(avctx, AV_LOG_ERROR, "invalid slice size %"PRIu32"\n",
                    slice_size);

             return AVERROR_INVALIDDATA;
         }
 
         if (AV_RL32(src + off) != slice_size - 16) {
             av_log(avctx, AV_LOG_ERROR,

                    "Slice sizes mismatch: got %"PRIu32" instead of %"PRIu32"\n",

                    AV_RL32(src + off), slice_size - 16);
         }
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
         dx2_decode_slice_rgb(&gb2, avctx->width, slice_height, dst,
                              pic->linesize[0]);
 
         dst += pic->linesize[0] * slice_height;
         off += slice_size;
     }
 
     return 0;
 }
 
 static int dx2_decode_slice_410(GetBitContext *gb, int width, int height,
                                 uint8_t *Y, uint8_t *U, uint8_t *V,
                                 int ystride, int ustride, int vstride)
 {
     int x, y, i, j;
     uint8_t lru[3][8];
 
     for (i = 0; i < 3; i++)
         memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
 
     for (y = 0; y < height; y += 4) {
         for (x = 0; x < width; x += 4) {
             for (j = 0; j < 4; j++)
                 for (i = 0; i < 4; i++)
                     Y[x + i + j * ystride] = decode_sym(gb, lru[0]);
             U[x >> 2] = decode_sym(gb, lru[1]) ^ 0x80;
             V[x >> 2] = decode_sym(gb, lru[2]) ^ 0x80;
         }
 
         Y += ystride << 2;
         U += ustride;
         V += vstride;
     }
 
     return 0;
 }
 
 static int dxtory_decode_v2_410(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
     GetByteContext gb;
     GetBitContext  gb2;
     int nslices, slice, slice_height, ref_slice_height;
     int cur_y, next_y;
     uint32_t off, slice_size;
     uint8_t *Y, *U, *V;
     int ret;
 
     bytestream2_init(&gb, src, src_size);
     nslices = bytestream2_get_le16(&gb);
     off = FFALIGN(nslices * 4 + 2, 16);
     if (src_size < off) {
         av_log(avctx, AV_LOG_ERROR, "no slice data\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!nslices || avctx->height % nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,
                               avctx->width, avctx->height);
         return AVERROR_PATCHWELCOME;
     }
 
     ref_slice_height = avctx->height / nslices;
     if ((avctx->width & 3) || (avctx->height & 3)) {
         avpriv_request_sample(avctx, "Frame dimensions %dx%d",
                               avctx->width, avctx->height);
     }
 
     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     Y = pic->data[0];
     U = pic->data[1];
     V = pic->data[2];
 
     cur_y  = 0;
     next_y = ref_slice_height;
     for (slice = 0; slice < nslices; slice++) {
         slice_size   = bytestream2_get_le32(&gb);
         slice_height = (next_y & ~3) - (cur_y & ~3);
         if (slice_size > src_size - off) {
             av_log(avctx, AV_LOG_ERROR,

                    "invalid slice size %"PRIu32" (only %"PRIu32" bytes left)\n",

                    slice_size, src_size - off);
             return AVERROR_INVALIDDATA;
         }
         if (slice_size <= 16) {

             av_log(avctx, AV_LOG_ERROR, "invalid slice size %"PRIu32"\n", slice_size);

             return AVERROR_INVALIDDATA;
         }
 
         if (AV_RL32(src + off) != slice_size - 16) {
             av_log(avctx, AV_LOG_ERROR,

                    "Slice sizes mismatch: got %"PRIu32" instead of %"PRIu32"\n",

                    AV_RL32(src + off), slice_size - 16);
         }
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
         dx2_decode_slice_410(&gb2, avctx->width, slice_height, Y, U, V,
                              pic->linesize[0], pic->linesize[1],
                              pic->linesize[2]);
 
         Y += pic->linesize[0] *  slice_height;
         U += pic->linesize[1] * (slice_height >> 2);
         V += pic->linesize[2] * (slice_height >> 2);
         off += slice_size;
         cur_y   = next_y;
         next_y += ref_slice_height;
     }
 
     return 0;
 }
 
 static int dx2_decode_slice_420(GetBitContext *gb, int width, int height,
                                 uint8_t *Y, uint8_t *U, uint8_t *V,
                                 int ystride, int ustride, int vstride)

 {
     int x, y, i;
     uint8_t lru[3][8];
 
     for (i = 0; i < 3; i++)
         memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
 
     for (y = 0; y < height; y+=2) {
         for (x = 0; x < width; x += 2) {
             Y[x + 0 + 0 * ystride] = decode_sym(gb, lru[0]);
             Y[x + 1 + 0 * ystride] = decode_sym(gb, lru[0]);
             Y[x + 0 + 1 * ystride] = decode_sym(gb, lru[0]);
             Y[x + 1 + 1 * ystride] = decode_sym(gb, lru[0]);
             U[x >> 1] = decode_sym(gb, lru[1]) ^ 0x80;
             V[x >> 1] = decode_sym(gb, lru[2]) ^ 0x80;
         }
 
         Y += ystride << 1;
         U += ustride;
         V += vstride;
     }
 
     return 0;
 }
 

 static int dxtory_decode_v2_420(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)

 {
     GetByteContext gb;
     GetBitContext  gb2;

     int nslices, slice, slice_height, ref_slice_height;
     int cur_y, next_y;

     uint32_t off, slice_size;
     uint8_t *Y, *U, *V;
     int ret;
 
     bytestream2_init(&gb, src, src_size);
     nslices = bytestream2_get_le16(&gb);
     off = FFALIGN(nslices * 4 + 2, 16);
     if (src_size < off) {
         av_log(avctx, AV_LOG_ERROR, "no slice data\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!nslices || avctx->height % nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,
                               avctx->width, avctx->height);

         return AVERROR_PATCHWELCOME;

     }
 

     ref_slice_height = avctx->height / nslices;
     if ((avctx->width & 1) || (avctx->height & 1)) {
         avpriv_request_sample(avctx, "Frame dimensions %dx%d",
                               avctx->width, avctx->height);

     }
 
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     Y = pic->data[0];
     U = pic->data[1];
     V = pic->data[2];
 

     cur_y  = 0;
     next_y = ref_slice_height;

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

         slice_size   = bytestream2_get_le32(&gb);
         slice_height = (next_y & ~1) - (cur_y & ~1);

         if (slice_size > src_size - off) {
             av_log(avctx, AV_LOG_ERROR,

                    "invalid slice size %"PRIu32" (only %"PRIu32" bytes left)\n",

                    slice_size, src_size - off);
             return AVERROR_INVALIDDATA;
         }
         if (slice_size <= 16) {

             av_log(avctx, AV_LOG_ERROR, "invalid slice size %"PRIu32"\n", slice_size);

             return AVERROR_INVALIDDATA;
         }
 
         if (AV_RL32(src + off) != slice_size - 16) {
             av_log(avctx, AV_LOG_ERROR,

                    "Slice sizes mismatch: got %"PRIu32" instead of %"PRIu32"\n",

                    AV_RL32(src + off), slice_size - 16);
         }
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);

         dx2_decode_slice_420(&gb2, avctx->width, slice_height, Y, U, V,
                              pic->linesize[0], pic->linesize[1],
                              pic->linesize[2]);

 
         Y += pic->linesize[0] *  slice_height;
         U += pic->linesize[1] * (slice_height >> 1);
         V += pic->linesize[2] * (slice_height >> 1);
         off += slice_size;

         cur_y   = next_y;
         next_y += ref_slice_height;

     }
 
     return 0;
 }
 

 static int dx2_decode_slice_444(GetBitContext *gb, int width, int height,
                                 uint8_t *Y, uint8_t *U, uint8_t *V,
                                 int ystride, int ustride, int vstride)
 {
     int x, y, i;
     uint8_t lru[3][8];
 
     for (i = 0; i < 3; i++)
         memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
 
     for (y = 0; y < height; y++) {
         for (x = 0; x < width; x++) {
             Y[x] = decode_sym(gb, lru[0]);
             U[x] = decode_sym(gb, lru[1]) ^ 0x80;
             V[x] = decode_sym(gb, lru[2]) ^ 0x80;
         }
 
         Y += ystride;
         U += ustride;
         V += vstride;
     }
 
     return 0;
 }
 
 static int dxtory_decode_v2_444(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
     GetByteContext gb;
     GetBitContext  gb2;
     int nslices, slice, slice_height;
     uint32_t off, slice_size;
     uint8_t *Y, *U, *V;
     int ret;
 
     bytestream2_init(&gb, src, src_size);
     nslices = bytestream2_get_le16(&gb);
     off = FFALIGN(nslices * 4 + 2, 16);
     if (src_size < off) {
         av_log(avctx, AV_LOG_ERROR, "no slice data\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!nslices || avctx->height % nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,
                               avctx->width, avctx->height);
         return AVERROR_PATCHWELCOME;
     }
 
     slice_height = avctx->height / nslices;
 
     avctx->pix_fmt = AV_PIX_FMT_YUV444P;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
     Y = pic->data[0];
     U = pic->data[1];
     V = pic->data[2];
 
     for (slice = 0; slice < nslices; slice++) {
         slice_size = bytestream2_get_le32(&gb);
         if (slice_size > src_size - off) {
             av_log(avctx, AV_LOG_ERROR,

                    "invalid slice size %"PRIu32" (only %"PRIu32" bytes left)\n",

                    slice_size, src_size - off);
             return AVERROR_INVALIDDATA;
         }
         if (slice_size <= 16) {

             av_log(avctx, AV_LOG_ERROR, "invalid slice size %"PRIu32"\n", slice_size);

             return AVERROR_INVALIDDATA;
         }
 
         if (AV_RL32(src + off) != slice_size - 16) {
             av_log(avctx, AV_LOG_ERROR,

                    "Slice sizes mismatch: got %"PRIu32" instead of %"PRIu32"\n",

                    AV_RL32(src + off), slice_size - 16);
         }
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
         dx2_decode_slice_444(&gb2, avctx->width, slice_height, Y, U, V,
                              pic->linesize[0], pic->linesize[1],
                              pic->linesize[2]);
 
         Y += pic->linesize[0] * slice_height;
         U += pic->linesize[1] * slice_height;
         V += pic->linesize[2] * slice_height;
         off += slice_size;
     }
 
     return 0;
 }
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                         AVPacket *avpkt)
 {
     AVFrame *pic = data;
     const uint8_t *src = avpkt->data;
     int ret;
 
     if (avpkt->size < 16) {
         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }
 
     switch (AV_RB32(src)) {

     case 0x01000001:
         ret = dxtory_decode_v1_rgb(avctx, pic, src + 16, avpkt->size - 16,
                                    AV_PIX_FMT_BGR24, 3);
         break;
     case 0x01000009:
         ret = dxtory_decode_v2_rgb(avctx, pic, src + 16, avpkt->size - 16);
         break;

     case 0x02000001:

         ret = dxtory_decode_v1_420(avctx, pic, src + 16, avpkt->size - 16);

         break;
     case 0x02000009:

         ret = dxtory_decode_v2_420(avctx, pic, src + 16, avpkt->size - 16);
         break;
     case 0x03000001:
         ret = dxtory_decode_v1_410(avctx, pic, src + 16, avpkt->size - 16);
         break;
     case 0x03000009:
         ret = dxtory_decode_v2_410(avctx, pic, src + 16, avpkt->size - 16);
         break;
     case 0x04000001:
         ret = dxtory_decode_v1_444(avctx, pic, src + 16, avpkt->size - 16);
         break;
     case 0x04000009:
         ret = dxtory_decode_v2_444(avctx, pic, src + 16, avpkt->size - 16);
         break;
     case 0x17000001:
         ret = dxtory_decode_v1_rgb(avctx, pic, src + 16, avpkt->size - 16,
                                    AV_PIX_FMT_RGB565LE, 2);
         break;

     case 0x17000009:
         ret = dxtory_decode_v2_565(avctx, pic, src + 16, avpkt->size - 16, 1);
         break;

     case 0x18000001:
     case 0x19000001:
         ret = dxtory_decode_v1_rgb(avctx, pic, src + 16, avpkt->size - 16,
                                    AV_PIX_FMT_RGB555LE, 2);

         break;

     case 0x18000009:
     case 0x19000009:
         ret = dxtory_decode_v2_565(avctx, pic, src + 16, avpkt->size - 16, 0);
         break;

     default:

         avpriv_request_sample(avctx, "Frame header %"PRIX32, AV_RB32(src));

         return AVERROR_PATCHWELCOME;
     }
 
     if (ret)
         return ret;
 
     pic->pict_type = AV_PICTURE_TYPE_I;
     pic->key_frame = 1;

     *got_frame = 1;

 
     return avpkt->size;
 }
 
 AVCodec ff_dxtory_decoder = {
     .name           = "dxtory",
     .long_name      = NULL_IF_CONFIG_SMALL("Dxtory"),
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_DXTORY,

     .decode         = decode_frame,
     .capabilities   = CODEC_CAP_DR1,
 };