/*
  * Copyright (c) 2010-2011 Maxim Poliakovski
  * Copyright (c) 2010-2011 Elvis Presley
  *
  * 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

  * Known FOURCCs: 'apch' (HQ), 'apcn' (SD), 'apcs' (LT), 'acpo' (Proxy), 'ap4h' (4444)

  */
 
 //#define DEBUG
 

 #define LONG_BITSTREAM_READER

 #include "libavutil/internal.h"

 #include "avcodec.h"
 #include "get_bits.h"

 #include "idctdsp.h"

 #include "internal.h"

 #include "simple_idct.h"

 #include "proresdec.h"

 #include "proresdata.h"

 
 static void permute(uint8_t *dst, const uint8_t *src, const uint8_t permutation[64])
 {
     int i;
     for (i = 0; i < 64; i++)
         dst[i] = permutation[src[i]];
 }
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     ProresContext *ctx = avctx->priv_data;

     uint8_t idct_permutation[64];

 
     avctx->bits_per_raw_sample = 10;
 

     ff_blockdsp_init(&ctx->bdsp, avctx);

     ff_proresdsp_init(&ctx->prodsp, avctx);

     ff_init_scantable_permutation(idct_permutation,
                                   ctx->prodsp.idct_permutation_type);
 

     permute(ctx->progressive_scan, ff_prores_progressive_scan, idct_permutation);
     permute(ctx->interlaced_scan, ff_prores_interlaced_scan, idct_permutation);

 
     return 0;
 }
 
 static int decode_frame_header(ProresContext *ctx, const uint8_t *buf,
                                const int data_size, AVCodecContext *avctx)
 {
     int hdr_size, width, height, flags;
     int version;
     const uint8_t *ptr;
 
     hdr_size = AV_RB16(buf);

     ff_dlog(avctx, "header size %d\n", hdr_size);

     if (hdr_size > data_size) {
         av_log(avctx, AV_LOG_ERROR, "error, wrong header size\n");

         return AVERROR_INVALIDDATA;

     }
 
     version = AV_RB16(buf + 2);

     ff_dlog(avctx, "%.4s version %d\n", buf+4, version);

     if (version > 1) {
         av_log(avctx, AV_LOG_ERROR, "unsupported version: %d\n", version);

         return AVERROR_PATCHWELCOME;

     }
 
     width  = AV_RB16(buf + 8);
     height = AV_RB16(buf + 10);
     if (width != avctx->width || height != avctx->height) {
         av_log(avctx, AV_LOG_ERROR, "picture resolution change: %dx%d -> %dx%d\n",
                avctx->width, avctx->height, width, height);

         return AVERROR_PATCHWELCOME;

     }
 
     ctx->frame_type = (buf[12] >> 2) & 3;

     ctx->alpha_info = buf[17] & 0xf;
 
     if (ctx->alpha_info > 2) {
         av_log(avctx, AV_LOG_ERROR, "Invalid alpha mode %d\n", ctx->alpha_info);
         return AVERROR_INVALIDDATA;
     }

     if (avctx->skip_alpha) ctx->alpha_info = 0;

     ff_dlog(avctx, "frame type %d\n", ctx->frame_type);

 
     if (ctx->frame_type == 0) {
         ctx->scan = ctx->progressive_scan; // permuted
     } else {
         ctx->scan = ctx->interlaced_scan; // permuted

         ctx->frame->interlaced_frame = 1;
         ctx->frame->top_field_first = ctx->frame_type == 1;

     }
 

     if (ctx->alpha_info) {
         avctx->pix_fmt = (buf[12] & 0xC0) == 0xC0 ? AV_PIX_FMT_YUVA444P10 : AV_PIX_FMT_YUVA422P10;
     } else {
         avctx->pix_fmt = (buf[12] & 0xC0) == 0xC0 ? AV_PIX_FMT_YUV444P10 : AV_PIX_FMT_YUV422P10;
     }

 
     ptr   = buf + 20;
     flags = buf[19];

     ff_dlog(avctx, "flags %x\n", flags);

 
     if (flags & 2) {

         if(buf + data_size - ptr < 64) {
             av_log(avctx, AV_LOG_ERROR, "Header truncated\n");

             return AVERROR_INVALIDDATA;

         }

         permute(ctx->qmat_luma, ctx->prodsp.idct_permutation, ptr);

         ptr += 64;
     } else {
         memset(ctx->qmat_luma, 4, 64);
     }
 
     if (flags & 1) {

         if(buf + data_size - ptr < 64) {
             av_log(avctx, AV_LOG_ERROR, "Header truncated\n");

             return AVERROR_INVALIDDATA;

         }

         permute(ctx->qmat_chroma, ctx->prodsp.idct_permutation, ptr);

     } else {
         memset(ctx->qmat_chroma, 4, 64);
     }
 
     return hdr_size;
 }
 
 static int decode_picture_header(AVCodecContext *avctx, const uint8_t *buf, const int buf_size)
 {
     ProresContext *ctx = avctx->priv_data;
     int i, hdr_size, slice_count;
     unsigned pic_data_size;
     int log2_slice_mb_width, log2_slice_mb_height;
     int slice_mb_count, mb_x, mb_y;
     const uint8_t *data_ptr, *index_ptr;
 
     hdr_size = buf[0] >> 3;
     if (hdr_size < 8 || hdr_size > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "error, wrong picture header size\n");

         return AVERROR_INVALIDDATA;

     }
 
     pic_data_size = AV_RB32(buf + 1);
     if (pic_data_size > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "error, wrong picture data size\n");

         return AVERROR_INVALIDDATA;

     }
 
     log2_slice_mb_width  = buf[7] >> 4;
     log2_slice_mb_height = buf[7] & 0xF;
     if (log2_slice_mb_width > 3 || log2_slice_mb_height) {
         av_log(avctx, AV_LOG_ERROR, "unsupported slice resolution: %dx%d\n",
                1 << log2_slice_mb_width, 1 << log2_slice_mb_height);

         return AVERROR_INVALIDDATA;

     }
 
     ctx->mb_width  = (avctx->width  + 15) >> 4;

     if (ctx->frame_type)
         ctx->mb_height = (avctx->height + 31) >> 5;
     else
         ctx->mb_height = (avctx->height + 15) >> 4;

     // QT ignores the written value
     // slice_count = AV_RB16(buf + 5);
     slice_count = ctx->mb_height * ((ctx->mb_width >> log2_slice_mb_width) +
                                     av_popcount(ctx->mb_width & (1 << log2_slice_mb_width) - 1));

 
     if (ctx->slice_count != slice_count || !ctx->slices) {
         av_freep(&ctx->slices);

         ctx->slice_count = 0;

         ctx->slices = av_mallocz_array(slice_count, sizeof(*ctx->slices));

         if (!ctx->slices)
             return AVERROR(ENOMEM);
         ctx->slice_count = slice_count;
     }
 
     if (!slice_count)
         return AVERROR(EINVAL);
 
     if (hdr_size + slice_count*2 > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "error, wrong slice count\n");

         return AVERROR_INVALIDDATA;

     }
 
     // parse slice information
     index_ptr = buf + hdr_size;
     data_ptr  = index_ptr + slice_count*2;
 
     slice_mb_count = 1 << log2_slice_mb_width;
     mb_x = 0;
     mb_y = 0;
 
     for (i = 0; i < slice_count; i++) {
         SliceContext *slice = &ctx->slices[i];
 
         slice->data = data_ptr;
         data_ptr += AV_RB16(index_ptr + i*2);
 
         while (ctx->mb_width - mb_x < slice_mb_count)
             slice_mb_count >>= 1;
 
         slice->mb_x = mb_x;
         slice->mb_y = mb_y;
         slice->mb_count = slice_mb_count;
         slice->data_size = data_ptr - slice->data;
 
         if (slice->data_size < 6) {
             av_log(avctx, AV_LOG_ERROR, "error, wrong slice data size\n");

             return AVERROR_INVALIDDATA;

         }
 
         mb_x += slice_mb_count;
         if (mb_x == ctx->mb_width) {
             slice_mb_count = 1 << log2_slice_mb_width;
             mb_x = 0;
             mb_y++;
         }
         if (data_ptr > buf + buf_size) {
             av_log(avctx, AV_LOG_ERROR, "error, slice out of bounds\n");

             return AVERROR_INVALIDDATA;

         }
     }
 

     if (mb_x || mb_y != ctx->mb_height) {
         av_log(avctx, AV_LOG_ERROR, "error wrong mb count y %d h %d\n",
                mb_y, ctx->mb_height);

         return AVERROR_INVALIDDATA;

     }
 

     return pic_data_size;
 }
 

 #define DECODE_CODEWORD(val, codebook, SKIP)                            \

     do {                                                                \
         unsigned int rice_order, exp_order, switch_bits;                \
         unsigned int q, buf, bits;                                      \
                                                                         \
         UPDATE_CACHE(re, gb);                                           \
         buf = GET_CACHE(re, gb);                                        \
                                                                         \
         /* number of bits to switch between rice and exp golomb */      \
         switch_bits =  codebook & 3;                                    \
         rice_order  =  codebook >> 5;                                   \
         exp_order   = (codebook >> 2) & 7;                              \
                                                                         \

         q = 31 - av_log2(buf);                                          \

                                                                         \
         if (q > switch_bits) { /* exp golomb */                         \
             bits = exp_order - switch_bits + (q<<1);                    \

             if (bits > FFMIN(MIN_CACHE_BITS, 31))                       \

                 return AVERROR_INVALIDDATA;                             \

             val = SHOW_UBITS(re, gb, bits) - (1 << exp_order) +         \
                 ((switch_bits + 1) << rice_order);                      \

             SKIP(re, gb, bits);                                         \

         } else if (rice_order) {                                        \
             SKIP_BITS(re, gb, q+1);                                     \
             val = (q << rice_order) + SHOW_UBITS(re, gb, rice_order);   \

             SKIP(re, gb, rice_order);                                   \

         } else {                                                        \
             val = q;                                                    \

             SKIP(re, gb, q+1);                                          \

         }                                                               \

     } while (0)

 
 #define TOSIGNED(x) (((x) >> 1) ^ (-((x) & 1)))
 
 #define FIRST_DC_CB 0xB8
 
 static const uint8_t dc_codebook[7] = { 0x04, 0x28, 0x28, 0x4D, 0x4D, 0x70, 0x70};
 

 static av_always_inline int decode_dc_coeffs(GetBitContext *gb, int16_t *out,

                                               int blocks_per_slice)

 {

     int16_t prev_dc;

     int code, i, sign;
 
     OPEN_READER(re, gb);
 

     DECODE_CODEWORD(code, FIRST_DC_CB, LAST_SKIP_BITS);

     prev_dc = TOSIGNED(code);

     out[0] = prev_dc;

 
     out += 64; // dc coeff for the next block
 
     code = 5;
     sign = 0;
     for (i = 1; i < blocks_per_slice; i++, out += 64) {

         DECODE_CODEWORD(code, dc_codebook[FFMIN(code, 6U)], LAST_SKIP_BITS);

         if(code) sign ^= -(code & 1);
         else     sign  = 0;
         prev_dc += (((code + 1) >> 1) ^ sign) - sign;

         out[0] = prev_dc;

     }
     CLOSE_READER(re, gb);

     return 0;

 }
 
 // adaptive codebook switching lut according to previous run/level values
 static const uint8_t run_to_cb[16] = { 0x06, 0x06, 0x05, 0x05, 0x04, 0x29, 0x29, 0x29, 0x29, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x4C };
 static const uint8_t lev_to_cb[10] = { 0x04, 0x0A, 0x05, 0x06, 0x04, 0x28, 0x28, 0x28, 0x28, 0x4C };
 

 static av_always_inline int decode_ac_coeffs(AVCodecContext *avctx, GetBitContext *gb,
                                              int16_t *out, int blocks_per_slice)

 {
     ProresContext *ctx = avctx->priv_data;
     int block_mask, sign;
     unsigned pos, run, level;
     int max_coeffs, i, bits_left;
     int log2_block_count = av_log2(blocks_per_slice);
 
     OPEN_READER(re, gb);

     UPDATE_CACHE(re, gb);                                           \

     run   = 4;
     level = 2;
 
     max_coeffs = 64 << log2_block_count;
     block_mask = blocks_per_slice - 1;
 
     for (pos = block_mask;;) {

         bits_left = gb->size_in_bits - re_index;

         if (!bits_left || (bits_left < 32 && !SHOW_UBITS(re, gb, bits_left)))
             break;
 

         DECODE_CODEWORD(run, run_to_cb[FFMIN(run,  15)], LAST_SKIP_BITS);

         pos += run + 1;
         if (pos >= max_coeffs) {
             av_log(avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", pos, max_coeffs);

             return AVERROR_INVALIDDATA;

         }
 

         DECODE_CODEWORD(level, lev_to_cb[FFMIN(level, 9)], SKIP_BITS);

         level += 1;
 
         i = pos >> log2_block_count;
 
         sign = SHOW_SBITS(re, gb, 1);
         SKIP_BITS(re, gb, 1);

         out[((pos & block_mask) << 6) + ctx->scan[i]] = ((level ^ sign) - sign);

     }
 
     CLOSE_READER(re, gb);

     return 0;

 }
 

 static int decode_slice_luma(AVCodecContext *avctx, SliceContext *slice,
                              uint16_t *dst, int dst_stride,
                              const uint8_t *buf, unsigned buf_size,
                              const int16_t *qmat)

 {
     ProresContext *ctx = avctx->priv_data;

     LOCAL_ALIGNED_32(int16_t, blocks, [8*4*64]);

     int16_t *block;

     GetBitContext gb;
     int i, blocks_per_slice = slice->mb_count<<2;

     int ret;

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

         ctx->bdsp.clear_block(blocks+(i<<6));

 
     init_get_bits(&gb, buf, buf_size << 3);
 

     if ((ret = decode_dc_coeffs(&gb, blocks, blocks_per_slice)) < 0)
         return ret;

     if ((ret = decode_ac_coeffs(avctx, &gb, blocks, blocks_per_slice)) < 0)
         return ret;

 
     block = blocks;
     for (i = 0; i < slice->mb_count; i++) {

         ctx->prodsp.idct_put(dst, dst_stride, block+(0<<6), qmat);

         ctx->prodsp.idct_put(dst             +8, dst_stride, block+(1<<6), qmat);
         ctx->prodsp.idct_put(dst+4*dst_stride  , dst_stride, block+(2<<6), qmat);
         ctx->prodsp.idct_put(dst+4*dst_stride+8, dst_stride, block+(3<<6), qmat);

         block += 4*64;

         dst += 16;

     }

     return 0;

 }
 

 static int decode_slice_chroma(AVCodecContext *avctx, SliceContext *slice,
                                uint16_t *dst, int dst_stride,
                                const uint8_t *buf, unsigned buf_size,
                                const int16_t *qmat, int log2_blocks_per_mb)

 {
     ProresContext *ctx = avctx->priv_data;

     LOCAL_ALIGNED_32(int16_t, blocks, [8*4*64]);

     int16_t *block;

     GetBitContext gb;
     int i, j, blocks_per_slice = slice->mb_count << log2_blocks_per_mb;

     int ret;

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

         ctx->bdsp.clear_block(blocks+(i<<6));

 
     init_get_bits(&gb, buf, buf_size << 3);
 

     if ((ret = decode_dc_coeffs(&gb, blocks, blocks_per_slice)) < 0)
         return ret;

     if ((ret = decode_ac_coeffs(avctx, &gb, blocks, blocks_per_slice)) < 0)
         return ret;

 
     block = blocks;
     for (i = 0; i < slice->mb_count; i++) {
         for (j = 0; j < log2_blocks_per_mb; j++) {

             ctx->prodsp.idct_put(dst,              dst_stride, block+(0<<6), qmat);

             ctx->prodsp.idct_put(dst+4*dst_stride, dst_stride, block+(1<<6), qmat);

             block += 2*64;

             dst += 8;

         }
     }

     return 0;

 }
 

 static void unpack_alpha(GetBitContext *gb, uint16_t *dst, int num_coeffs,
                          const int num_bits)
 {
     const int mask = (1 << num_bits) - 1;
     int i, idx, val, alpha_val;
 
     idx       = 0;
     alpha_val = mask;
     do {
         do {
             if (get_bits1(gb)) {
                 val = get_bits(gb, num_bits);
             } else {
                 int sign;
                 val  = get_bits(gb, num_bits == 16 ? 7 : 4);
                 sign = val & 1;
                 val  = (val + 2) >> 1;
                 if (sign)
                     val = -val;
             }
             alpha_val = (alpha_val + val) & mask;
             if (num_bits == 16) {
                 dst[idx++] = alpha_val >> 6;
             } else {
                 dst[idx++] = (alpha_val << 2) | (alpha_val >> 6);
             }

             if (idx >= num_coeffs)

                 break;
         } while (get_bits_left(gb)>0 && get_bits1(gb));
         val = get_bits(gb, 4);
         if (!val)
             val = get_bits(gb, 11);
         if (idx + val > num_coeffs)
             val = num_coeffs - idx;
         if (num_bits == 16) {
             for (i = 0; i < val; i++)
                 dst[idx++] = alpha_val >> 6;
         } else {
             for (i = 0; i < val; i++)
                 dst[idx++] = (alpha_val << 2) | (alpha_val >> 6);
 
         }
     } while (idx < num_coeffs);
 }
 
 /**
  * Decode alpha slice plane.
  */
 static void decode_slice_alpha(ProresContext *ctx,
                                uint16_t *dst, int dst_stride,
                                const uint8_t *buf, int buf_size,
                                int blocks_per_slice)
 {
     GetBitContext gb;
     int i;

     LOCAL_ALIGNED_32(int16_t, blocks, [8*4*64]);

     int16_t *block;
 
     for (i = 0; i < blocks_per_slice<<2; i++)

         ctx->bdsp.clear_block(blocks+(i<<6));

 
     init_get_bits(&gb, buf, buf_size << 3);
 
     if (ctx->alpha_info == 2) {
         unpack_alpha(&gb, blocks, blocks_per_slice * 4 * 64, 16);
     } else {
         unpack_alpha(&gb, blocks, blocks_per_slice * 4 * 64, 8);
     }
 
     block = blocks;
     for (i = 0; i < 16; i++) {
         memcpy(dst, block, 16 * blocks_per_slice * sizeof(*dst));
         dst   += dst_stride >> 1;
         block += 16 * blocks_per_slice;
     }
 }
 

 static int decode_slice_thread(AVCodecContext *avctx, void *arg, int jobnr, int threadnr)
 {
     ProresContext *ctx = avctx->priv_data;
     SliceContext *slice = &ctx->slices[jobnr];
     const uint8_t *buf = slice->data;

     AVFrame *pic = ctx->frame;

     int i, hdr_size, qscale, log2_chroma_blocks_per_mb;
     int luma_stride, chroma_stride;

     int y_data_size, u_data_size, v_data_size, a_data_size;
     uint8_t *dest_y, *dest_u, *dest_v, *dest_a;

     LOCAL_ALIGNED_16(int16_t, qmat_luma_scaled,  [64]);
     LOCAL_ALIGNED_16(int16_t, qmat_chroma_scaled,[64]);

     int mb_x_shift;

     int ret;

     slice->ret = -1;

     //av_log(avctx, AV_LOG_INFO, "slice %d mb width %d mb x %d y %d\n",
     //       jobnr, slice->mb_count, slice->mb_x, slice->mb_y);
 
     // slice header
     hdr_size = buf[0] >> 3;
     qscale = av_clip(buf[1], 1, 224);
     qscale = qscale > 128 ? qscale - 96 << 2: qscale;
     y_data_size = AV_RB16(buf + 2);
     u_data_size = AV_RB16(buf + 4);
     v_data_size = slice->data_size - y_data_size - u_data_size - hdr_size;
     if (hdr_size > 7) v_data_size = AV_RB16(buf + 6);

     a_data_size = slice->data_size - y_data_size - u_data_size -
                   v_data_size - hdr_size;

     if (y_data_size < 0 || u_data_size < 0 || v_data_size < 0
         || hdr_size+y_data_size+u_data_size+v_data_size > slice->data_size){

         av_log(avctx, AV_LOG_ERROR, "invalid plane data size\n");

         return AVERROR_INVALIDDATA;

     }
 
     buf += hdr_size;
 
     for (i = 0; i < 64; i++) {

         qmat_luma_scaled  [i] = ctx->qmat_luma  [i] * qscale;

         qmat_chroma_scaled[i] = ctx->qmat_chroma[i] * qscale;
     }
 
     if (ctx->frame_type == 0) {
         luma_stride   = pic->linesize[0];
         chroma_stride = pic->linesize[1];
     } else {
         luma_stride   = pic->linesize[0] << 1;
         chroma_stride = pic->linesize[1] << 1;
     }
 

     if (avctx->pix_fmt == AV_PIX_FMT_YUV444P10 || avctx->pix_fmt == AV_PIX_FMT_YUVA444P10) {

         mb_x_shift = 5;
         log2_chroma_blocks_per_mb = 2;
     } else {
         mb_x_shift = 4;
         log2_chroma_blocks_per_mb = 1;
     }
 
     dest_y = pic->data[0] + (slice->mb_y << 4) * luma_stride + (slice->mb_x << 5);
     dest_u = pic->data[1] + (slice->mb_y << 4) * chroma_stride + (slice->mb_x << mb_x_shift);
     dest_v = pic->data[2] + (slice->mb_y << 4) * chroma_stride + (slice->mb_x << mb_x_shift);

     dest_a = pic->data[3] + (slice->mb_y << 4) * luma_stride + (slice->mb_x << 5);

     if (ctx->frame_type && ctx->first_field ^ ctx->frame->top_field_first) {

         dest_y += pic->linesize[0];
         dest_u += pic->linesize[1];
         dest_v += pic->linesize[2];

         dest_a += pic->linesize[3];

     }
 

     ret = decode_slice_luma(avctx, slice, (uint16_t*)dest_y, luma_stride,
                             buf, y_data_size, qmat_luma_scaled);
     if (ret < 0)
         return ret;

     if (!(avctx->flags & AV_CODEC_FLAG_GRAY) && (u_data_size + v_data_size) > 0) {

         ret = decode_slice_chroma(avctx, slice, (uint16_t*)dest_u, chroma_stride,
                                   buf + y_data_size, u_data_size,
                                   qmat_chroma_scaled, log2_chroma_blocks_per_mb);
         if (ret < 0)
             return ret;
 
         ret = decode_slice_chroma(avctx, slice, (uint16_t*)dest_v, chroma_stride,
                                   buf + y_data_size + u_data_size, v_data_size,
                                   qmat_chroma_scaled, log2_chroma_blocks_per_mb);
         if (ret < 0)
             return ret;

     }

     else {
         size_t mb_max_x = slice->mb_count << (mb_x_shift - 1);
         for (size_t i = 0; i < 16; ++i)
             for (size_t j = 0; j < mb_max_x; ++j) {
                 *(uint16_t*)(dest_u + (i * chroma_stride) + (j << 1)) = 511;
                 *(uint16_t*)(dest_v + (i * chroma_stride) + (j << 1)) = 511;
             }
     }
 

     /* decode alpha plane if available */

     if (ctx->alpha_info && pic->data[3] && a_data_size)

         decode_slice_alpha(ctx, (uint16_t*)dest_a, luma_stride,
                            buf + y_data_size + u_data_size + v_data_size,
                            a_data_size, slice->mb_count);

     slice->ret = 0;

     return 0;
 }
 
 static int decode_picture(AVCodecContext *avctx)
 {
     ProresContext *ctx = avctx->priv_data;

     int i;

     int error = 0;

     avctx->execute2(avctx, decode_slice_thread, NULL, NULL, ctx->slice_count);

 
     for (i = 0; i < ctx->slice_count; i++)

         error += ctx->slices[i].ret < 0;

     if (error)

         ctx->frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;

     if (error < ctx->slice_count)
         return 0;
 
     return ctx->slices[0].ret;

 }
 

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

                         AVPacket *avpkt)
 {
     ProresContext *ctx = avctx->priv_data;

     AVFrame *frame = data;

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     int frame_hdr_size, pic_size, ret;

     if (buf_size < 28 || AV_RL32(buf + 4) != AV_RL32("icpf")) {

         av_log(avctx, AV_LOG_ERROR, "invalid frame header\n");

         return AVERROR_INVALIDDATA;

     }
 

     ctx->frame = frame;

     ctx->frame->pict_type = AV_PICTURE_TYPE_I;
     ctx->frame->key_frame = 1;

     ctx->first_field = 1;
 
     buf += 8;
     buf_size -= 8;
 
     frame_hdr_size = decode_frame_header(ctx, buf, buf_size, avctx);
     if (frame_hdr_size < 0)

         return frame_hdr_size;

 
     buf += frame_hdr_size;
     buf_size -= frame_hdr_size;
 

     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;

  decode_picture:
     pic_size = decode_picture_header(avctx, buf, buf_size);
     if (pic_size < 0) {
         av_log(avctx, AV_LOG_ERROR, "error decoding picture header\n");

         return pic_size;

     }
 

     if ((ret = decode_picture(avctx)) < 0) {

         av_log(avctx, AV_LOG_ERROR, "error decoding picture\n");

         return ret;

     }
 
     buf += pic_size;
     buf_size -= pic_size;
 
     if (ctx->frame_type && buf_size > 0 && ctx->first_field) {
         ctx->first_field = 0;
         goto decode_picture;
     }
 

     *got_frame      = 1;

 
     return avpkt->size;
 }
 
 static av_cold int decode_close(AVCodecContext *avctx)
 {
     ProresContext *ctx = avctx->priv_data;
 
     av_freep(&ctx->slices);
 
     return 0;
 }
 

 AVCodec ff_prores_decoder = {
     .name           = "prores",

     .long_name      = NULL_IF_CONFIG_SMALL("ProRes"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_PRORES,

     .priv_data_size = sizeof(ProresContext),
     .init           = decode_init,
     .close          = decode_close,
     .decode         = decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS,

 };