/*
  * Apple ProRes compatible decoder
  *
  * Copyright (c) 2010-2011 Maxim Poliakovski
  *

  * 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
  * This is a decoder for Apple ProRes 422 SD/HQ/LT/Proxy and ProRes 4444.
  * It is used for storing and editing high definition video data in Apple's Final Cut Pro.
  *
  * @see http://wiki.multimedia.cx/index.php?title=Apple_ProRes
  */
 

 #define LONG_BITSTREAM_READER // some ProRes vlc codes require up to 28 bits to be read at once

 
 #include <stdint.h>
 
 #include "libavutil/intmath.h"
 #include "avcodec.h"

 #include "dsputil.h"

 #include "internal.h"

 #include "proresdata.h"

 #include "proresdsp.h"

 #include "get_bits.h"
 

 typedef struct {

     const uint8_t *index;            ///< pointers to the data of this slice
     int slice_num;
     int x_pos, y_pos;
     int slice_width;

     int prev_slice_sf;               ///< scalefactor of the previous decoded slice

     DECLARE_ALIGNED(16, int16_t, blocks)[8 * 4 * 64];

     DECLARE_ALIGNED(16, int16_t, qmat_luma_scaled)[64];
     DECLARE_ALIGNED(16, int16_t, qmat_chroma_scaled)[64];

 } ProresThreadData;

 
 typedef struct {

     ProresDSPContext dsp;

     AVFrame    *frame;

     ScanTable  scantable;
     int        scantable_type;           ///< -1 = uninitialized, 0 = progressive, 1/2 = interlaced
 
     int        frame_type;               ///< 0 = progressive, 1 = top-field first, 2 = bottom-field first
     int        pic_format;               ///< 2 = 422, 3 = 444
     uint8_t    qmat_luma[64];            ///< dequantization matrix for luma
     uint8_t    qmat_chroma[64];          ///< dequantization matrix for chroma
     int        qmat_changed;             ///< 1 - global quantization matrices changed
     int        total_slices;            ///< total number of slices in a picture

     ProresThreadData *slice_data;
     int        pic_num;

     int        chroma_factor;
     int        mb_chroma_factor;
     int        num_chroma_blocks;       ///< number of chrominance blocks in a macroblock
     int        num_x_slices;
     int        num_y_slices;
     int        slice_width_factor;
     int        slice_height_factor;
     int        num_x_mbs;
     int        num_y_mbs;

     int        alpha_info;

 } ProresContext;
 
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     ProresContext *ctx = avctx->priv_data;
 
     ctx->total_slices     = 0;

     ctx->slice_data       = NULL;

     avctx->bits_per_raw_sample = PRORES_BITS_PER_SAMPLE;

     ff_proresdsp_init(&ctx->dsp, avctx);

 
     ctx->scantable_type = -1;   // set scantable type to uninitialized
     memset(ctx->qmat_luma, 4, 64);
     memset(ctx->qmat_chroma, 4, 64);
 
     return 0;
 }
 
 
 static int decode_frame_header(ProresContext *ctx, const uint8_t *buf,
                                const int data_size, AVCodecContext *avctx)
 {
     int hdr_size, version, width, height, flags;
     const uint8_t *ptr;
 
     hdr_size = AV_RB16(buf);
     if (hdr_size > data_size) {

         av_log(avctx, AV_LOG_ERROR, "frame data too small\n");

         return AVERROR_INVALIDDATA;

     }
 
     version = AV_RB16(buf + 2);
     if (version >= 2) {
         av_log(avctx, AV_LOG_ERROR,
                "unsupported header version: %d\n", version);

         return AVERROR_INVALIDDATA;

     }
 
     width  = AV_RB16(buf + 8);
     height = AV_RB16(buf + 10);
     if (width != avctx->width || height != avctx->height) {
         av_log(avctx, AV_LOG_ERROR,

                "picture dimension changed: old: %d x %d, new: %d x %d\n",

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

         return AVERROR_INVALIDDATA;

     }
 
     ctx->frame_type = (buf[12] >> 2) & 3;
     if (ctx->frame_type > 2) {
         av_log(avctx, AV_LOG_ERROR,

                "unsupported frame type: %d\n", ctx->frame_type);

         return AVERROR_INVALIDDATA;

     }
 
     ctx->chroma_factor     = (buf[12] >> 6) & 3;
     ctx->mb_chroma_factor  = ctx->chroma_factor + 2;
     ctx->num_chroma_blocks = (1 << ctx->chroma_factor) >> 1;

     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;

     switch (ctx->chroma_factor) {
     case 2:

         avctx->pix_fmt = ctx->alpha_info ? AV_PIX_FMT_YUVA422P10
                                          : AV_PIX_FMT_YUV422P10;

         break;
     case 3:

         avctx->pix_fmt = ctx->alpha_info ? AV_PIX_FMT_YUVA444P10
                                          : AV_PIX_FMT_YUV444P10;

         break;
     default:
         av_log(avctx, AV_LOG_ERROR,

                "unsupported picture format: %d\n", ctx->pic_format);

         return AVERROR_INVALIDDATA;

     }
 
     if (ctx->scantable_type != ctx->frame_type) {
         if (!ctx->frame_type)
             ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable,

                               ff_prores_progressive_scan);

         else
             ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable,

                               ff_prores_interlaced_scan);

         ctx->scantable_type = ctx->frame_type;
     }
 
     if (ctx->frame_type) {      /* if interlaced */

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

     } else {

         ctx->frame->interlaced_frame = 0;

     }
 

     avctx->color_primaries = buf[14];
     avctx->color_trc       = buf[15];
     avctx->colorspace      = buf[16];
 

     ctx->qmat_changed = 0;
     ptr   = buf + 20;
     flags = buf[19];
     if (flags & 2) {
         if (ptr - buf > hdr_size - 64) {

             av_log(avctx, AV_LOG_ERROR, "header data too small\n");

             return AVERROR_INVALIDDATA;

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

             av_log(avctx, AV_LOG_ERROR, "header data too small\n");

             return -1;
         }
         if (memcmp(ctx->qmat_chroma, ptr, 64)) {
             memcpy(ctx->qmat_chroma, ptr, 64);
             ctx->qmat_changed = 1;
         }
     } else {
         memset(ctx->qmat_chroma, 4, 64);
         ctx->qmat_changed = 1;
     }
 
     return hdr_size;
 }
 
 
 static int decode_picture_header(ProresContext *ctx, const uint8_t *buf,
                                  const int data_size, AVCodecContext *avctx)
 {
     int   i, hdr_size, pic_data_size, num_slices;
     int   slice_width_factor, slice_height_factor;
     int   remainder, num_x_slices;
     const uint8_t *data_ptr, *index_ptr;
 
     hdr_size = data_size > 0 ? buf[0] >> 3 : 0;
     if (hdr_size < 8 || hdr_size > data_size) {

         av_log(avctx, AV_LOG_ERROR, "picture header too small\n");

         return AVERROR_INVALIDDATA;

     }
 
     pic_data_size = AV_RB32(buf + 1);
     if (pic_data_size > data_size) {

         av_log(avctx, AV_LOG_ERROR, "picture data too small\n");

         return AVERROR_INVALIDDATA;

     }
 
     slice_width_factor  = buf[7] >> 4;
     slice_height_factor = buf[7] & 0xF;
     if (slice_width_factor > 3 || slice_height_factor) {
         av_log(avctx, AV_LOG_ERROR,

                "unsupported slice dimension: %d x %d\n",

                1 << slice_width_factor, 1 << slice_height_factor);

         return AVERROR_INVALIDDATA;

     }
 
     ctx->slice_width_factor  = slice_width_factor;
     ctx->slice_height_factor = slice_height_factor;
 
     ctx->num_x_mbs = (avctx->width + 15) >> 4;

     ctx->num_y_mbs = (avctx->height +

                       (1 << (4 + ctx->frame->interlaced_frame)) - 1) >>
                      (4 + ctx->frame->interlaced_frame);

 
     remainder    = ctx->num_x_mbs & ((1 << slice_width_factor) - 1);
     num_x_slices = (ctx->num_x_mbs >> slice_width_factor) + (remainder & 1) +
                    ((remainder >> 1) & 1) + ((remainder >> 2) & 1);
 
     num_slices = num_x_slices * ctx->num_y_mbs;
     if (num_slices != AV_RB16(buf + 5)) {

         av_log(avctx, AV_LOG_ERROR, "invalid number of slices\n");

         return AVERROR_INVALIDDATA;

     }
 
     if (ctx->total_slices != num_slices) {

         av_freep(&ctx->slice_data);
         ctx->slice_data = av_malloc((num_slices + 1) * sizeof(ctx->slice_data[0]));
         if (!ctx->slice_data)

             return AVERROR(ENOMEM);
         ctx->total_slices = num_slices;
     }
 
     if (hdr_size + num_slices * 2 > data_size) {

         av_log(avctx, AV_LOG_ERROR, "slice table too small\n");

         return AVERROR_INVALIDDATA;

     }
 
     /* parse slice table allowing quick access to the slice data */
     index_ptr = buf + hdr_size;
     data_ptr = index_ptr + num_slices * 2;
 
     for (i = 0; i < num_slices; i++) {

         ctx->slice_data[i].index = data_ptr;

         ctx->slice_data[i].prev_slice_sf = 0;

         data_ptr += AV_RB16(index_ptr + i * 2);
     }

     ctx->slice_data[i].index = data_ptr;

     ctx->slice_data[i].prev_slice_sf = 0;

 
     if (data_ptr > buf + data_size) {

         av_log(avctx, AV_LOG_ERROR, "out of slice data\n");

         return -1;
     }
 
     return pic_data_size;
 }
 
 
 /**
  * Read an unsigned rice/exp golomb codeword.
  */

 static inline int decode_vlc_codeword(GetBitContext *gb, unsigned codebook)

 {
     unsigned int rice_order, exp_order, switch_bits;
     unsigned int buf, code;
     int log, prefix_len, len;
 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf = GET_CACHE(re, gb);
 
     /* number of prefix bits to switch between Rice and expGolomb */
     switch_bits = (codebook & 3) + 1;
     rice_order  = codebook >> 5;        /* rice code order */
     exp_order   = (codebook >> 2) & 7;  /* exp golomb code order */
 
     log = 31 - av_log2(buf); /* count prefix bits (zeroes) */
 
     if (log < switch_bits) { /* ok, we got a rice code */
         if (!rice_order) {
             /* shortcut for faster decoding of rice codes without remainder */
             code = log;
             LAST_SKIP_BITS(re, gb, log + 1);
         } else {
             prefix_len = log + 1;

             code = (log << rice_order) + NEG_USR32(buf << prefix_len, rice_order);

             LAST_SKIP_BITS(re, gb, prefix_len + rice_order);
         }
     } else { /* otherwise we got a exp golomb code */
         len  = (log << 1) - switch_bits + exp_order + 1;
         code = NEG_USR32(buf, len) - (1 << exp_order) + (switch_bits << rice_order);
         LAST_SKIP_BITS(re, gb, len);
     }
 
     CLOSE_READER(re, gb);
 
     return code;
 }
 
 #define LSB2SIGN(x) (-((x) & 1))
 #define TOSIGNED(x) (((x) >> 1) ^ LSB2SIGN(x))
 
 /**
  * Decode DC coefficients for all blocks in a slice.
  */

 static inline void decode_dc_coeffs(GetBitContext *gb, int16_t *out,

                                     int nblocks)
 {

     int16_t prev_dc;

     int     i, sign;
     int16_t delta;
     unsigned int code;
 
     code   = decode_vlc_codeword(gb, FIRST_DC_CB);
     out[0] = prev_dc = TOSIGNED(code);
 
     out   += 64; /* move to the DC coeff of the next block */
     delta  = 3;
 
     for (i = 1; i < nblocks; i++, out += 64) {

         code = decode_vlc_codeword(gb, ff_prores_dc_codebook[FFMIN(FFABS(delta), 3)]);

 
         sign     = -(((delta >> 15) & 1) ^ (code & 1));
         delta    = (((code + 1) >> 1) ^ sign) - sign;
         prev_dc += delta;
         out[0]   = prev_dc;
     }
 }
 
 
 /**
  * Decode AC coefficients for all blocks in a slice.
  */

 static inline int decode_ac_coeffs(GetBitContext *gb, int16_t *out,
                                    int blocks_per_slice,
                                    int plane_size_factor,
                                    const uint8_t *scan)

 {
     int pos, block_mask, run, level, sign, run_cb_index, lev_cb_index;
     int max_coeffs, bits_left;
 
     /* set initial prediction values */
     run   = 4;
     level = 2;
 
     max_coeffs = blocks_per_slice << 6;
     block_mask = blocks_per_slice - 1;
 
     for (pos = blocks_per_slice - 1; pos < max_coeffs;) {

         run_cb_index = ff_prores_run_to_cb_index[FFMIN(run, 15)];
         lev_cb_index = ff_prores_lev_to_cb_index[FFMIN(level, 9)];

 
         bits_left = get_bits_left(gb);

         if (bits_left <= 0 || (bits_left <= 8 && !show_bits(gb, bits_left)))

             return 0;

         run = decode_vlc_codeword(gb, ff_prores_ac_codebook[run_cb_index]);

         if (run < 0)
             return AVERROR_INVALIDDATA;

 
         bits_left = get_bits_left(gb);

         if (bits_left <= 0 || (bits_left <= 8 && !show_bits(gb, bits_left)))

             return AVERROR_INVALIDDATA;

         level = decode_vlc_codeword(gb, ff_prores_ac_codebook[lev_cb_index]) + 1;

         if (level < 0)
             return AVERROR_INVALIDDATA;

 
         pos += run + 1;
         if (pos >= max_coeffs)
             break;
 
         sign = get_sbits(gb, 1);
         out[((pos & block_mask) << 6) + scan[pos >> plane_size_factor]] =
             (level ^ sign) - sign;
     }

 
     return 0;

 }
 
 
 /**
  * Decode a slice plane (luma or chroma).
  */

 static int decode_slice_plane(ProresContext *ctx, ProresThreadData *td,
                               const uint8_t *buf,
                               int data_size, uint16_t *out_ptr,
                               int linesize, int mbs_per_slice,
                               int blocks_per_mb, int plane_size_factor,
                               const int16_t *qmat, int is_chroma)

 {
     GetBitContext gb;

     int16_t *block_ptr;

     int mb_num, blocks_per_slice, ret;

 
     blocks_per_slice = mbs_per_slice * blocks_per_mb;
 

     memset(td->blocks, 0, 8 * 4 * 64 * sizeof(*td->blocks));

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

     decode_dc_coeffs(&gb, td->blocks, blocks_per_slice);

     ret = decode_ac_coeffs(&gb, td->blocks, blocks_per_slice,
                            plane_size_factor, ctx->scantable.permutated);
     if (ret < 0)
         return ret;

 
     /* inverse quantization, inverse transform and output */

     block_ptr = td->blocks;

     if (!is_chroma) {
         for (mb_num = 0; mb_num < mbs_per_slice; mb_num++, out_ptr += blocks_per_mb * 4) {
             ctx->dsp.idct_put(out_ptr,                    linesize, block_ptr, qmat);

             block_ptr += 64;

             if (blocks_per_mb > 2) {
                 ctx->dsp.idct_put(out_ptr + 8,            linesize, block_ptr, qmat);
                 block_ptr += 64;
             }
             ctx->dsp.idct_put(out_ptr + linesize * 4,     linesize, block_ptr, qmat);

             block_ptr += 64;

             if (blocks_per_mb > 2) {
                 ctx->dsp.idct_put(out_ptr + linesize * 4 + 8, linesize, block_ptr, qmat);
                 block_ptr += 64;
             }

         }

     } else {
         for (mb_num = 0; mb_num < mbs_per_slice; mb_num++, out_ptr += blocks_per_mb * 4) {
             ctx->dsp.idct_put(out_ptr,                    linesize, block_ptr, qmat);
             block_ptr += 64;
             ctx->dsp.idct_put(out_ptr + linesize * 4,     linesize, block_ptr, qmat);

             block_ptr += 64;

             if (blocks_per_mb > 2) {
                 ctx->dsp.idct_put(out_ptr + 8,            linesize, block_ptr, qmat);
                 block_ptr += 64;
                 ctx->dsp.idct_put(out_ptr + linesize * 4 + 8, linesize, block_ptr, qmat);
                 block_ptr += 64;
             }

         }

     }

     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_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_alpha_plane(ProresContext *ctx, ProresThreadData *td,
                                const uint8_t *buf, int data_size,
                                uint16_t *out_ptr, int linesize,
                                int mbs_per_slice)
 {
     GetBitContext gb;
     int i;
     uint16_t *block_ptr;
 
     memset(td->blocks, 0, 8 * 4 * 64 * sizeof(*td->blocks));
 
     init_get_bits(&gb, buf, data_size << 3);
 
     if (ctx->alpha_info == 2)
         unpack_alpha(&gb, td->blocks, mbs_per_slice * 4 * 64, 16);
     else
         unpack_alpha(&gb, td->blocks, mbs_per_slice * 4 * 64, 8);
 
     block_ptr = td->blocks;
 
     for (i = 0; i < 16; i++) {
         memcpy(out_ptr, block_ptr, 16 * mbs_per_slice * sizeof(*out_ptr));
         out_ptr   += linesize >> 1;
         block_ptr += 16 * mbs_per_slice;
     }
 }
 

 static int decode_slice(AVCodecContext *avctx, void *tdata)

 {

     ProresThreadData *td = tdata;

     ProresContext *ctx = avctx->priv_data;
     int mb_x_pos  = td->x_pos;
     int mb_y_pos  = td->y_pos;
     int pic_num   = ctx->pic_num;
     int slice_num = td->slice_num;
     int mbs_per_slice = td->slice_width;

     const uint8_t *buf;

     uint8_t *y_data, *u_data, *v_data, *a_data;

     AVFrame *pic = ctx->frame;

     int i, sf, slice_width_factor;

     int slice_data_size, hdr_size;
     int y_data_size, u_data_size, v_data_size, a_data_size;
     int y_linesize, u_linesize, v_linesize, a_linesize;

     int coff[4];

     int ret;

     buf             = ctx->slice_data[slice_num].index;
     slice_data_size = ctx->slice_data[slice_num + 1].index - buf;

 
     slice_width_factor = av_log2(mbs_per_slice);
 
     y_data     = pic->data[0];
     u_data     = pic->data[1];
     v_data     = pic->data[2];

     a_data     = pic->data[3];

     y_linesize = pic->linesize[0];
     u_linesize = pic->linesize[1];
     v_linesize = pic->linesize[2];

     a_linesize = pic->linesize[3];

 
     if (pic->interlaced_frame) {
         if (!(pic_num ^ pic->top_field_first)) {
             y_data += y_linesize;
             u_data += u_linesize;
             v_data += v_linesize;

             if (a_data)
                 a_data += a_linesize;

         }
         y_linesize <<= 1;
         u_linesize <<= 1;
         v_linesize <<= 1;

         a_linesize <<= 1;

     }

     y_data += (mb_y_pos << 4) * y_linesize + (mb_x_pos << 5);
     u_data += (mb_y_pos << 4) * u_linesize + (mb_x_pos << ctx->mb_chroma_factor);
     v_data += (mb_y_pos << 4) * v_linesize + (mb_x_pos << ctx->mb_chroma_factor);
     if (a_data)
         a_data += (mb_y_pos << 4) * a_linesize + (mb_x_pos << 5);

 
     if (slice_data_size < 6) {

         av_log(avctx, AV_LOG_ERROR, "slice data too small\n");

         return AVERROR_INVALIDDATA;

     }
 
     /* parse slice header */
     hdr_size    = buf[0] >> 3;

     coff[0]     = hdr_size;

     y_data_size = AV_RB16(buf + 2);

     coff[1]     = coff[0] + y_data_size;

     u_data_size = AV_RB16(buf + 4);

     coff[2]     = coff[1] + u_data_size;
     v_data_size = hdr_size > 7 ? AV_RB16(buf + 6) : slice_data_size - coff[2];
     coff[3]     = coff[2] + v_data_size;

     a_data_size = ctx->alpha_info ? slice_data_size - coff[3] : 0;

 
     /* if V or alpha component size is negative that means that previous
        component sizes are too large */
     if (v_data_size < 0 || a_data_size < 0 || hdr_size < 6) {

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

         return AVERROR_INVALIDDATA;

     }
 
     sf = av_clip(buf[1], 1, 224);
     sf = sf > 128 ? (sf - 96) << 2 : sf;
 
     /* scale quantization matrixes according with slice's scale factor */

     /* TODO: this can be SIMD-optimized a lot */

     if (ctx->qmat_changed || sf != td->prev_slice_sf) {
         td->prev_slice_sf = sf;

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

             td->qmat_luma_scaled[ctx->dsp.idct_permutation[i]]   = ctx->qmat_luma[i]   * sf;
             td->qmat_chroma_scaled[ctx->dsp.idct_permutation[i]] = ctx->qmat_chroma[i] * sf;

         }
     }
 
     /* decode luma plane */

     ret = decode_slice_plane(ctx, td, buf + coff[0], y_data_size,
                              (uint16_t*) y_data, y_linesize,
                              mbs_per_slice, 4, slice_width_factor + 2,
                              td->qmat_luma_scaled, 0);
 
     if (ret < 0)
         return ret;

 
     /* decode U chroma plane */

     ret = decode_slice_plane(ctx, td, buf + coff[1], u_data_size,
                              (uint16_t*) u_data, u_linesize,
                              mbs_per_slice, ctx->num_chroma_blocks,
                              slice_width_factor + ctx->chroma_factor - 1,
                              td->qmat_chroma_scaled, 1);
     if (ret < 0)
         return ret;

 
     /* decode V chroma plane */

     ret = decode_slice_plane(ctx, td, buf + coff[2], v_data_size,
                              (uint16_t*) v_data, v_linesize,
                              mbs_per_slice, ctx->num_chroma_blocks,
                              slice_width_factor + ctx->chroma_factor - 1,
                              td->qmat_chroma_scaled, 1);
     if (ret < 0)
         return ret;

     /* decode alpha plane if available */
     if (a_data && a_data_size)

         decode_alpha_plane(ctx, td, buf + coff[3], a_data_size,
                            (uint16_t*) a_data, a_linesize,

                            mbs_per_slice);
 

     return 0;
 }
 
 
 static int decode_picture(ProresContext *ctx, int pic_num,
                           AVCodecContext *avctx)
 {
     int slice_num, slice_width, x_pos, y_pos;
 
     slice_num = 0;
 

     ctx->pic_num = pic_num;

     for (y_pos = 0; y_pos < ctx->num_y_mbs; y_pos++) {
         slice_width = 1 << ctx->slice_width_factor;
 
         for (x_pos = 0; x_pos < ctx->num_x_mbs && slice_width;
              x_pos += slice_width) {
             while (ctx->num_x_mbs - x_pos < slice_width)
                 slice_width >>= 1;
 

             ctx->slice_data[slice_num].slice_num   = slice_num;
             ctx->slice_data[slice_num].x_pos       = x_pos;
             ctx->slice_data[slice_num].y_pos       = y_pos;
             ctx->slice_data[slice_num].slice_width = slice_width;

 
             slice_num++;
         }
     }
 

     return avctx->execute(avctx, decode_slice,

                           ctx->slice_data, NULL, slice_num,
                           sizeof(ctx->slice_data[0]));

 }
 
 
 #define MOVE_DATA_PTR(nbytes) buf += (nbytes); buf_size -= (nbytes)
 

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

                         AVPacket *avpkt)
 {
     ProresContext *ctx = avctx->priv_data;
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;
     int frame_hdr_size, pic_num, pic_data_size;
 

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

     /* check frame atom container */
     if (buf_size < 28 || buf_size < AV_RB32(buf) ||
         AV_RB32(buf + 4) != FRAME_ID) {
         av_log(avctx, AV_LOG_ERROR, "invalid frame\n");

         return AVERROR_INVALIDDATA;

     }
 
     MOVE_DATA_PTR(8);
 
     frame_hdr_size = decode_frame_header(ctx, buf, buf_size, avctx);
     if (frame_hdr_size < 0)

         return AVERROR_INVALIDDATA;

 
     MOVE_DATA_PTR(frame_hdr_size);
 

     if (ff_get_buffer(avctx, ctx->frame, 0) < 0)

         return -1;
 

     for (pic_num = 0; ctx->frame->interlaced_frame - pic_num + 1; pic_num++) {

         pic_data_size = decode_picture_header(ctx, buf, buf_size, avctx);
         if (pic_data_size < 0)

             return AVERROR_INVALIDDATA;

 
         if (decode_picture(ctx, pic_num, avctx))
             return -1;
 
         MOVE_DATA_PTR(pic_data_size);
     }
 

     ctx->frame = NULL;
     *got_frame = 1;

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

     av_freep(&ctx->slice_data);

 
     return 0;
 }
 
 
 AVCodec ff_prores_lgpl_decoder = {

     .name           = "prores_lgpl",

     .long_name      = NULL_IF_CONFIG_SMALL("Apple ProRes (iCodec Pro)"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_PRORES,

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

     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,

 };