h264.c

/*
 * H.26L/H.264/AVC/JVT/14496-10/... decoder
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * 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
 * H.264 / AVC / MPEG4 part10 codec.
 * @author Michael Niedermayer <michaelni@gmx.at>
 */

#define UNCHECKED_BITSTREAM_READER 1

#include "libavutil/avassert.h"
#include "libavutil/display.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/stereo3d.h"
#include "libavutil/timer.h"
#include "internal.h"
#include "cabac.h"
#include "cabac_functions.h"
#include "error_resilience.h"
#include "avcodec.h"
#include "h264.h"
#include "h264data.h"
#include "h264chroma.h"
#include "h264_mvpred.h"
#include "golomb.h"
#include "mathops.h"
#include "me_cmp.h"
#include "mpegutils.h"
#include "rectangle.h"
#include "svq3.h"
#include "thread.h"
#include "vdpau_internal.h"

#include <assert.h>

const uint16_t ff_h264_mb_sizes[4] = { 256, 384, 512, 768 };

int avpriv_h264_has_num_reorder_frames(AVCodecContext *avctx)
{
    H264Context *h = avctx->priv_data;
    return h ? h->sps.num_reorder_frames : 0;
}

static void h264_er_decode_mb(void *opaque, int ref, int mv_dir, int mv_type,
                              int (*mv)[2][4][2],
                              int mb_x, int mb_y, int mb_intra, int mb_skipped)
{
    H264Context *h = opaque;

    h->mb_x  = mb_x;
    h->mb_y  = mb_y;
    h->mb_xy = mb_x + mb_y * h->mb_stride;
    memset(h->non_zero_count_cache, 0, sizeof(h->non_zero_count_cache));
    av_assert1(ref >= 0);
    /* FIXME: It is possible albeit uncommon that slice references
     * differ between slices. We take the easy approach and ignore
     * it for now. If this turns out to have any relevance in
     * practice then correct remapping should be added. */
    if (ref >= h->ref_count[0])
        ref = 0;
    if (!h->ref_list[0][ref].f.data[0]) {
        av_log(h->avctx, AV_LOG_DEBUG, "Reference not available for error concealing\n");
        ref = 0;
    }
    if ((h->ref_list[0][ref].reference&3) != 3) {
        av_log(h->avctx, AV_LOG_DEBUG, "Reference invalid\n");
        return;
    }
    fill_rectangle(&h->cur_pic.ref_index[0][4 * h->mb_xy],
                   2, 2, 2, ref, 1);
    fill_rectangle(&h->ref_cache[0][scan8[0]], 4, 4, 8, ref, 1);
    fill_rectangle(h->mv_cache[0][scan8[0]], 4, 4, 8,
                   pack16to32((*mv)[0][0][0], (*mv)[0][0][1]), 4);
    h->mb_mbaff =
    h->mb_field_decoding_flag = 0;
    ff_h264_hl_decode_mb(h);
}

void ff_h264_draw_horiz_band(H264Context *h, int y, int height)
{
    AVCodecContext *avctx = h->avctx;
    AVFrame *cur  = &h->cur_pic.f;
    AVFrame *last = h->ref_list[0][0].f.data[0] ? &h->ref_list[0][0].f : NULL;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
    int vshift = desc->log2_chroma_h;
    const int field_pic = h->picture_structure != PICT_FRAME;
    if (field_pic) {
        height <<= 1;
        y      <<= 1;
    }

    height = FFMIN(height, avctx->height - y);

    if (field_pic && h->first_field && !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD))
        return;

    if (avctx->draw_horiz_band) {
        AVFrame *src;
        int offset[AV_NUM_DATA_POINTERS];
        int i;

        if (cur->pict_type == AV_PICTURE_TYPE_B || h->low_delay ||
            (avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
            src = cur;
        else if (last)
            src = last;
        else
            return;

        offset[0] = y * src->linesize[0];
        offset[1] =
        offset[2] = (y >> vshift) * src->linesize[1];
        for (i = 3; i < AV_NUM_DATA_POINTERS; i++)
            offset[i] = 0;

        emms_c();

        avctx->draw_horiz_band(avctx, src, offset,
                               y, h->picture_structure, height);
    }
}

/**
 * Check if the top & left blocks are available if needed and
 * change the dc mode so it only uses the available blocks.
 */
int ff_h264_check_intra4x4_pred_mode(H264Context *h)
{
    static const int8_t top[12] = {
        -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
    };
    static const int8_t left[12] = {
        0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
    };
    int i;

    if (!(h->top_samples_available & 0x8000)) {
        for (i = 0; i < 4; i++) {
            int status = top[h->intra4x4_pred_mode_cache[scan8[0] + i]];
            if (status < 0) {
                av_log(h->avctx, AV_LOG_ERROR,
                       "top block unavailable for requested intra4x4 mode %d at %d %d\n",
                       status, h->mb_x, h->mb_y);
                return AVERROR_INVALIDDATA;
            } else if (status) {
                h->intra4x4_pred_mode_cache[scan8[0] + i] = status;
            }
        }
    }

    if ((h->left_samples_available & 0x8888) != 0x8888) {
        static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
        for (i = 0; i < 4; i++)
            if (!(h->left_samples_available & mask[i])) {
                int status = left[h->intra4x4_pred_mode_cache[scan8[0] + 8 * i]];
                if (status < 0) {
                    av_log(h->avctx, AV_LOG_ERROR,
                           "left block unavailable for requested intra4x4 mode %d at %d %d\n",
                           status, h->mb_x, h->mb_y);
                    return AVERROR_INVALIDDATA;
                } else if (status) {
                    h->intra4x4_pred_mode_cache[scan8[0] + 8 * i] = status;
                }
            }
    }

    return 0;
} // FIXME cleanup like ff_h264_check_intra_pred_mode

/**
 * Check if the top & left blocks are available if needed and
 * change the dc mode so it only uses the available blocks.
 */
int ff_h264_check_intra_pred_mode(H264Context *h, int mode, int is_chroma)
{
    static const int8_t top[4]  = { LEFT_DC_PRED8x8, 1, -1, -1 };
    static const int8_t left[5] = { TOP_DC_PRED8x8, -1,  2, -1, DC_128_PRED8x8 };

    if (mode > 3U) {
        av_log(h->avctx, AV_LOG_ERROR,
               "out of range intra chroma pred mode at %d %d\n",
               h->mb_x, h->mb_y);
        return AVERROR_INVALIDDATA;
    }

    if (!(h->top_samples_available & 0x8000)) {
        mode = top[mode];
        if (mode < 0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "top block unavailable for requested intra mode at %d %d\n",
                   h->mb_x, h->mb_y);
            return AVERROR_INVALIDDATA;
        }
    }

    if ((h->left_samples_available & 0x8080) != 0x8080) {
        mode = left[mode];
        if (is_chroma && (h->left_samples_available & 0x8080)) {
            // mad cow disease mode, aka MBAFF + constrained_intra_pred
            mode = ALZHEIMER_DC_L0T_PRED8x8 +
                   (!(h->left_samples_available & 0x8000)) +
                   2 * (mode == DC_128_PRED8x8);
        }
        if (mode < 0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "left block unavailable for requested intra mode at %d %d\n",
                   h->mb_x, h->mb_y);
            return AVERROR_INVALIDDATA;
        }
    }

    return mode;
}

const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src,
                                  int *dst_length, int *consumed, int length)
{
    int i, si, di;
    uint8_t *dst;
    int bufidx;

    // src[0]&0x80; // forbidden bit
    h->nal_ref_idc   = src[0] >> 5;
    h->nal_unit_type = src[0] & 0x1F;

    src++;
    length--;

#define STARTCODE_TEST                                                  \
    if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {         \
        if (src[i + 2] != 3 && src[i + 2] != 0) {                       \
            /* startcode, so we must be past the end */                 \
            length = i;                                                 \
        }                                                               \
        break;                                                          \
    }

#if HAVE_FAST_UNALIGNED
#define FIND_FIRST_ZERO                                                 \
    if (i > 0 && !src[i])                                               \
        i--;                                                            \
    while (src[i])                                                      \
        i++

#if HAVE_FAST_64BIT
    for (i = 0; i + 1 < length; i += 9) {
        if (!((~AV_RN64A(src + i) &
               (AV_RN64A(src + i) - 0x0100010001000101ULL)) &
              0x8000800080008080ULL))
            continue;
        FIND_FIRST_ZERO;
        STARTCODE_TEST;
        i -= 7;
    }
#else
    for (i = 0; i + 1 < length; i += 5) {
        if (!((~AV_RN32A(src + i) &
               (AV_RN32A(src + i) - 0x01000101U)) &
              0x80008080U))
            continue;
        FIND_FIRST_ZERO;
        STARTCODE_TEST;
        i -= 3;
    }
#endif
#else
    for (i = 0; i + 1 < length; i += 2) {
        if (src[i])
            continue;
        if (i > 0 && src[i - 1] == 0)
            i--;
        STARTCODE_TEST;
    }
#endif

    // use second escape buffer for inter data
    bufidx = h->nal_unit_type == NAL_DPC ? 1 : 0;

    av_fast_padded_malloc(&h->rbsp_buffer[bufidx], &h->rbsp_buffer_size[bufidx], length+MAX_MBPAIR_SIZE);
    dst = h->rbsp_buffer[bufidx];

    if (!dst)
        return NULL;

    if(i>=length-1){ //no escaped 0
        *dst_length= length;
        *consumed= length+1; //+1 for the header
        if(h->avctx->flags2 & CODEC_FLAG2_FAST){
            return src;
        }else{
            memcpy(dst, src, length);
            return dst;
        }
    }

    memcpy(dst, src, i);
    si = di = i;
    while (si + 2 < length) {
        // remove escapes (very rare 1:2^22)
        if (src[si + 2] > 3) {
            dst[di++] = src[si++];
            dst[di++] = src[si++];
        } else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
            if (src[si + 2] == 3) { // escape
                dst[di++]  = 0;
                dst[di++]  = 0;
                si        += 3;
                continue;
            } else // next start code
                goto nsc;
        }

        dst[di++] = src[si++];
    }
    while (si < length)
        dst[di++] = src[si++];

nsc:
    memset(dst + di, 0, FF_INPUT_BUFFER_PADDING_SIZE);

    *dst_length = di;
    *consumed   = si + 1; // +1 for the header
    /* FIXME store exact number of bits in the getbitcontext
     * (it is needed for decoding) */
    return dst;
}

/**
 * Identify the exact end of the bitstream
 * @return the length of the trailing, or 0 if damaged
 */
static int decode_rbsp_trailing(H264Context *h, const uint8_t *src)
{
    int v = *src;
    int r;

    tprintf(h->avctx, "rbsp trailing %X\n", v);

    for (r = 1; r < 9; r++) {
        if (v & 1)
            return r;
        v >>= 1;
    }
    return 0;
}

void ff_h264_free_tables(H264Context *h, int free_rbsp)
{
    int i;
    H264Context *hx;

    av_freep(&h->intra4x4_pred_mode);
    av_freep(&h->chroma_pred_mode_table);
    av_freep(&h->cbp_table);
    av_freep(&h->mvd_table[0]);
    av_freep(&h->mvd_table[1]);
    av_freep(&h->direct_table);
    av_freep(&h->non_zero_count);
    av_freep(&h->slice_table_base);
    h->slice_table = NULL;
    av_freep(&h->list_counts);

    av_freep(&h->mb2b_xy);
    av_freep(&h->mb2br_xy);

    av_buffer_pool_uninit(&h->qscale_table_pool);
    av_buffer_pool_uninit(&h->mb_type_pool);
    av_buffer_pool_uninit(&h->motion_val_pool);
    av_buffer_pool_uninit(&h->ref_index_pool);

    if (free_rbsp && h->DPB) {
        for (i = 0; i < H264_MAX_PICTURE_COUNT; i++)
            ff_h264_unref_picture(h, &h->DPB[i]);
        av_freep(&h->DPB);
    } else if (h->DPB) {
        for (i = 0; i < H264_MAX_PICTURE_COUNT; i++)
            h->DPB[i].needs_realloc = 1;
    }

    h->cur_pic_ptr = NULL;

    for (i = 0; i < H264_MAX_THREADS; i++) {
        hx = h->thread_context[i];
        if (!hx)
            continue;
        av_freep(&hx->top_borders[1]);
        av_freep(&hx->top_borders[0]);
        av_freep(&hx->bipred_scratchpad);
        av_freep(&hx->edge_emu_buffer);
        av_freep(&hx->dc_val_base);
        av_freep(&hx->er.mb_index2xy);
        av_freep(&hx->er.error_status_table);
        av_freep(&hx->er.er_temp_buffer);
        av_freep(&hx->er.mbintra_table);
        av_freep(&hx->er.mbskip_table);

        if (free_rbsp) {
            av_freep(&hx->rbsp_buffer[1]);
            av_freep(&hx->rbsp_buffer[0]);
            hx->rbsp_buffer_size[0] = 0;
            hx->rbsp_buffer_size[1] = 0;
        }
        if (i)
            av_freep(&h->thread_context[i]);
    }
}

int ff_h264_alloc_tables(H264Context *h)
{
    const int big_mb_num = h->mb_stride * (h->mb_height + 1);
    const int row_mb_num = 2*h->mb_stride*FFMAX(h->avctx->thread_count, 1);
    int x, y, i;

    FF_ALLOCZ_OR_GOTO(h->avctx, h->intra4x4_pred_mode,
                      row_mb_num * 8 * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->non_zero_count,
                      big_mb_num * 48 * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->slice_table_base,
                      (big_mb_num + h->mb_stride) * sizeof(*h->slice_table_base), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->cbp_table,
                      big_mb_num * sizeof(uint16_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->chroma_pred_mode_table,
                      big_mb_num * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mvd_table[0],
                      16 * row_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mvd_table[1],
                      16 * row_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->direct_table,
                      4 * big_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->list_counts,
                      big_mb_num * sizeof(uint8_t), fail)

    memset(h->slice_table_base, -1,
           (big_mb_num + h->mb_stride) * sizeof(*h->slice_table_base));
    h->slice_table = h->slice_table_base + h->mb_stride * 2 + 1;

    FF_ALLOCZ_OR_GOTO(h->avctx, h->mb2b_xy,
                      big_mb_num * sizeof(uint32_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mb2br_xy,
                      big_mb_num * sizeof(uint32_t), fail);
    for (y = 0; y < h->mb_height; y++)
        for (x = 0; x < h->mb_width; x++) {
            const int mb_xy = x + y * h->mb_stride;
            const int b_xy  = 4 * x + 4 * y * h->b_stride;

            h->mb2b_xy[mb_xy]  = b_xy;
            h->mb2br_xy[mb_xy] = 8 * (FMO ? mb_xy : (mb_xy % (2 * h->mb_stride)));
        }

    if (!h->dequant4_coeff[0])
        h264_init_dequant_tables(h);

    if (!h->DPB) {
        h->DPB = av_mallocz_array(H264_MAX_PICTURE_COUNT, sizeof(*h->DPB));
        if (!h->DPB)
            goto fail;
        for (i = 0; i < H264_MAX_PICTURE_COUNT; i++)
            av_frame_unref(&h->DPB[i].f);
        av_frame_unref(&h->cur_pic.f);
    }

    return 0;

fail:
    ff_h264_free_tables(h, 1);
    return AVERROR(ENOMEM);
}

/**
 * Init context
 * Allocate buffers which are not shared amongst multiple threads.
 */
int ff_h264_context_init(H264Context *h)
{
    ERContext *er = &h->er;
    int mb_array_size = h->mb_height * h->mb_stride;
    int y_size  = (2 * h->mb_width + 1) * (2 * h->mb_height + 1);
    int c_size  = h->mb_stride * (h->mb_height + 1);
    int yc_size = y_size + 2   * c_size;
    int x, y, i;

    FF_ALLOCZ_OR_GOTO(h->avctx, h->top_borders[0],
                      h->mb_width * 16 * 3 * sizeof(uint8_t) * 2, fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->top_borders[1],
                      h->mb_width * 16 * 3 * sizeof(uint8_t) * 2, fail)

    h->ref_cache[0][scan8[5]  + 1] =
    h->ref_cache[0][scan8[7]  + 1] =
    h->ref_cache[0][scan8[13] + 1] =
    h->ref_cache[1][scan8[5]  + 1] =
    h->ref_cache[1][scan8[7]  + 1] =
    h->ref_cache[1][scan8[13] + 1] = PART_NOT_AVAILABLE;

    if (CONFIG_ERROR_RESILIENCE) {
        /* init ER */
        er->avctx          = h->avctx;
        er->mecc           = &h->mecc;
        er->decode_mb      = h264_er_decode_mb;
        er->opaque         = h;
        er->quarter_sample = 1;

        er->mb_num      = h->mb_num;
        er->mb_width    = h->mb_width;
        er->mb_height   = h->mb_height;
        er->mb_stride   = h->mb_stride;
        er->b8_stride   = h->mb_width * 2 + 1;

        // error resilience code looks cleaner with this
        FF_ALLOCZ_OR_GOTO(h->avctx, er->mb_index2xy,
                          (h->mb_num + 1) * sizeof(int), fail);

        for (y = 0; y < h->mb_height; y++)
            for (x = 0; x < h->mb_width; x++)
                er->mb_index2xy[x + y * h->mb_width] = x + y * h->mb_stride;

        er->mb_index2xy[h->mb_height * h->mb_width] = (h->mb_height - 1) *
                                                      h->mb_stride + h->mb_width;

        FF_ALLOCZ_OR_GOTO(h->avctx, er->error_status_table,
                          mb_array_size * sizeof(uint8_t), fail);

        FF_ALLOC_OR_GOTO(h->avctx, er->mbintra_table, mb_array_size, fail);
        memset(er->mbintra_table, 1, mb_array_size);

        FF_ALLOCZ_OR_GOTO(h->avctx, er->mbskip_table, mb_array_size + 2, fail);

        FF_ALLOC_OR_GOTO(h->avctx, er->er_temp_buffer,
                         h->mb_height * h->mb_stride, fail);

        FF_ALLOCZ_OR_GOTO(h->avctx, h->dc_val_base,
                          yc_size * sizeof(int16_t), fail);
        er->dc_val[0] = h->dc_val_base + h->mb_width * 2 + 2;
        er->dc_val[1] = h->dc_val_base + y_size + h->mb_stride + 1;
        er->dc_val[2] = er->dc_val[1] + c_size;
        for (i = 0; i < yc_size; i++)
            h->dc_val_base[i] = 1024;
    }

    return 0;

fail:
    return AVERROR(ENOMEM); // ff_h264_free_tables will clean up for us
}

static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                            int parse_extradata);

int ff_h264_decode_extradata(H264Context *h, const uint8_t *buf, int size)
{
    AVCodecContext *avctx = h->avctx;
    int ret;

    if (!buf || size <= 0)
        return -1;

    if (buf[0] == 1) {
        int i, cnt, nalsize;
        const unsigned char *p = buf;

        h->is_avc = 1;

        if (size < 7) {
            av_log(avctx, AV_LOG_ERROR,
                   "avcC %d too short\n", size);
            return AVERROR_INVALIDDATA;
        }
        /* sps and pps in the avcC always have length coded with 2 bytes,
         * so put a fake nal_length_size = 2 while parsing them */
        h->nal_length_size = 2;
        // Decode sps from avcC
        cnt = *(p + 5) & 0x1f; // Number of sps
        p  += 6;
        for (i = 0; i < cnt; i++) {
            nalsize = AV_RB16(p) + 2;
            if(nalsize > size - (p-buf))
                return AVERROR_INVALIDDATA;
            ret = decode_nal_units(h, p, nalsize, 1);
            if (ret < 0) {
                av_log(avctx, AV_LOG_ERROR,
                       "Decoding sps %d from avcC failed\n", i);
                return ret;
            }
            p += nalsize;
        }
        // Decode pps from avcC
        cnt = *(p++); // Number of pps
        for (i = 0; i < cnt; i++) {
            nalsize = AV_RB16(p) + 2;
            if(nalsize > size - (p-buf))
                return AVERROR_INVALIDDATA;
            ret = decode_nal_units(h, p, nalsize, 1);
            if (ret < 0) {
                av_log(avctx, AV_LOG_ERROR,
                       "Decoding pps %d from avcC failed\n", i);
                return ret;
            }
            p += nalsize;
        }
        // Store right nal length size that will be used to parse all other nals
        h->nal_length_size = (buf[4] & 0x03) + 1;
    } else {
        h->is_avc = 0;
        ret = decode_nal_units(h, buf, size, 1);
        if (ret < 0)
            return ret;
    }
    return size;
}

av_cold int ff_h264_decode_init(AVCodecContext *avctx)
{
    H264Context *h = avctx->priv_data;
    int i;
    int ret;

    h->avctx = avctx;

    h->bit_depth_luma    = 8;
    h->chroma_format_idc = 1;

    h->avctx->bits_per_raw_sample = 8;
    h->cur_chroma_format_idc = 1;

    ff_h264dsp_init(&h->h264dsp, 8, 1);
    av_assert0(h->sps.bit_depth_chroma == 0);
    ff_h264chroma_init(&h->h264chroma, h->sps.bit_depth_chroma);
    ff_h264qpel_init(&h->h264qpel, 8);
    ff_h264_pred_init(&h->hpc, h->avctx->codec_id, 8, 1);

    h->dequant_coeff_pps = -1;
    h->current_sps_id = -1;

    /* needed so that IDCT permutation is known early */
    if (CONFIG_ERROR_RESILIENCE)
        ff_me_cmp_init(&h->mecc, h->avctx);
    ff_videodsp_init(&h->vdsp, 8);

    memset(h->pps.scaling_matrix4, 16, 6 * 16 * sizeof(uint8_t));
    memset(h->pps.scaling_matrix8, 16, 2 * 64 * sizeof(uint8_t));

    h->picture_structure   = PICT_FRAME;
    h->slice_context_count = 1;
    h->workaround_bugs     = avctx->workaround_bugs;
    h->flags               = avctx->flags;

    /* set defaults */
    // s->decode_mb = ff_h263_decode_mb;
    if (!avctx->has_b_frames)
        h->low_delay = 1;

    avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;

    ff_h264_decode_init_vlc();

    ff_init_cabac_states();

    h->pixel_shift        = 0;
    h->sps.bit_depth_luma = avctx->bits_per_raw_sample = 8;

    h->thread_context[0] = h;
    h->outputed_poc      = h->next_outputed_poc = INT_MIN;
    for (i = 0; i < MAX_DELAYED_PIC_COUNT; i++)
        h->last_pocs[i] = INT_MIN;
    h->prev_poc_msb = 1 << 16;
    h->prev_frame_num = -1;
    h->x264_build   = -1;
    h->sei_fpa.frame_packing_arrangement_cancel_flag = -1;
    ff_h264_reset_sei(h);
    if (avctx->codec_id == AV_CODEC_ID_H264) {
        if (avctx->ticks_per_frame == 1) {
            if(h->avctx->time_base.den < INT_MAX/2) {
                h->avctx->time_base.den *= 2;
            } else
                h->avctx->time_base.num /= 2;
        }
        avctx->ticks_per_frame = 2;
    }

    if (avctx->extradata_size > 0 && avctx->extradata) {
        ret = ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size);
        if (ret < 0) {
            ff_h264_free_context(h);
            return ret;
        }
    }

    if (h->sps.bitstream_restriction_flag &&
        h->avctx->has_b_frames < h->sps.num_reorder_frames) {
        h->avctx->has_b_frames = h->sps.num_reorder_frames;
        h->low_delay           = 0;
    }

    avctx->internal->allocate_progress = 1;

    ff_h264_flush_change(h);

    return 0;
}

static int decode_init_thread_copy(AVCodecContext *avctx)
{
    H264Context *h = avctx->priv_data;

    if (!avctx->internal->is_copy)
        return 0;
    memset(h->sps_buffers, 0, sizeof(h->sps_buffers));
    memset(h->pps_buffers, 0, sizeof(h->pps_buffers));

    h->rbsp_buffer[0] = NULL;
    h->rbsp_buffer[1] = NULL;
    h->rbsp_buffer_size[0] = 0;
    h->rbsp_buffer_size[1] = 0;
    h->context_initialized = 0;

    return 0;
}

/**
 * Run setup operations that must be run after slice header decoding.
 * This includes finding the next displayed frame.
 *
 * @param h h264 master context
 * @param setup_finished enough NALs have been read that we can call
 * ff_thread_finish_setup()
 */
static void decode_postinit(H264Context *h, int setup_finished)
{
    H264Picture *out = h->cur_pic_ptr;
    H264Picture *cur = h->cur_pic_ptr;
    int i, pics, out_of_order, out_idx;

    h->cur_pic_ptr->f.pict_type = h->pict_type;

    if (h->next_output_pic)
        return;

    if (cur->field_poc[0] == INT_MAX || cur->field_poc[1] == INT_MAX) {
        /* FIXME: if we have two PAFF fields in one packet, we can't start
         * the next thread here. If we have one field per packet, we can.
         * The check in decode_nal_units() is not good enough to find this
         * yet, so we assume the worst for now. */
        // if (setup_finished)
        //    ff_thread_finish_setup(h->avctx);
        return;
    }

    cur->f.interlaced_frame = 0;
    cur->f.repeat_pict      = 0;

    /* Signal interlacing information externally. */
    /* Prioritize picture timing SEI information over used
     * decoding process if it exists. */

    if (h->sps.pic_struct_present_flag) {
        switch (h->sei_pic_struct) {
        case SEI_PIC_STRUCT_FRAME:
            break;
        case SEI_PIC_STRUCT_TOP_FIELD:
        case SEI_PIC_STRUCT_BOTTOM_FIELD:
            cur->f.interlaced_frame = 1;
            break;
        case SEI_PIC_STRUCT_TOP_BOTTOM:
        case SEI_PIC_STRUCT_BOTTOM_TOP:
            if (FIELD_OR_MBAFF_PICTURE(h))
                cur->f.interlaced_frame = 1;
            else
                // try to flag soft telecine progressive
                cur->f.interlaced_frame = h->prev_interlaced_frame;
            break;
        case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
        case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
            /* Signal the possibility of telecined film externally
             * (pic_struct 5,6). From these hints, let the applications
             * decide if they apply deinterlacing. */
            cur->f.repeat_pict = 1;
            break;
        case SEI_PIC_STRUCT_FRAME_DOUBLING:
            cur->f.repeat_pict = 2;
            break;
        case SEI_PIC_STRUCT_FRAME_TRIPLING:
            cur->f.repeat_pict = 4;
            break;
        }

        if ((h->sei_ct_type & 3) &&
            h->sei_pic_struct <= SEI_PIC_STRUCT_BOTTOM_TOP)
            cur->f.interlaced_frame = (h->sei_ct_type & (1 << 1)) != 0;
    } else {
        /* Derive interlacing flag from used decoding process. */
        cur->f.interlaced_frame = FIELD_OR_MBAFF_PICTURE(h);
    }
    h->prev_interlaced_frame = cur->f.interlaced_frame;

    if (cur->field_poc[0] != cur->field_poc[1]) {
        /* Derive top_field_first from field pocs. */
        cur->f.top_field_first = cur->field_poc[0] < cur->field_poc[1];
    } else {
        if (cur->f.interlaced_frame || h->sps.pic_struct_present_flag) {
            /* Use picture timing SEI information. Even if it is a
             * information of a past frame, better than nothing. */
            if (h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM ||
                h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
                cur->f.top_field_first = 1;
            else
                cur->f.top_field_first = 0;
        } else {
            /* Most likely progressive */
            cur->f.top_field_first = 0;
        }
    }

    if (h->sei_frame_packing_present &&
        h->frame_packing_arrangement_type >= 0 &&
        h->frame_packing_arrangement_type <= 6 &&
        h->content_interpretation_type > 0 &&
        h->content_interpretation_type < 3) {
        AVStereo3D *stereo = av_stereo3d_create_side_data(&cur->f);
        if (stereo) {
        switch (h->frame_packing_arrangement_type) {
        case 0:
            stereo->type = AV_STEREO3D_CHECKERBOARD;
            break;
        case 1:
            stereo->type = AV_STEREO3D_COLUMNS;
            break;
        case 2:
            stereo->type = AV_STEREO3D_LINES;
            break;
        case 3:
            if (h->quincunx_subsampling)
                stereo->type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
            else
                stereo->type = AV_STEREO3D_SIDEBYSIDE;
            break;
        case 4:
            stereo->type = AV_STEREO3D_TOPBOTTOM;
            break;
        case 5:
            stereo->type = AV_STEREO3D_FRAMESEQUENCE;
            break;
        case 6:
            stereo->type = AV_STEREO3D_2D;
            break;
        }

        if (h->content_interpretation_type == 2)
            stereo->flags = AV_STEREO3D_FLAG_INVERT;
        }
    }

    if (h->sei_display_orientation_present &&
        (h->sei_anticlockwise_rotation || h->sei_hflip || h->sei_vflip)) {
        double angle = h->sei_anticlockwise_rotation * 360 / (double) (1 << 16);
        AVFrameSideData *rotation = av_frame_new_side_data(&cur->f,
                                                           AV_FRAME_DATA_DISPLAYMATRIX,
                                                           sizeof(int32_t) * 9);
        if (rotation) {
            av_display_rotation_set((int32_t *)rotation->data, angle);
            av_display_matrix_flip((int32_t *)rotation->data,
                                   h->sei_vflip, h->sei_hflip);
        }
    }

    cur->mmco_reset = h->mmco_reset;
    h->mmco_reset = 0;

    // FIXME do something with unavailable reference frames

    /* Sort B-frames into display order */

    if (h->sps.bitstream_restriction_flag &&
        h->avctx->has_b_frames < h->sps.num_reorder_frames) {
        h->avctx->has_b_frames = h->sps.num_reorder_frames;
        h->low_delay           = 0;
    }

    if (h->avctx->strict_std_compliance >= FF_COMPLIANCE_STRICT &&
        !h->sps.bitstream_restriction_flag) {
        h->avctx->has_b_frames = MAX_DELAYED_PIC_COUNT - 1;
        h->low_delay           = 0;
    }

    for (i = 0; 1; i++) {
        if(i == MAX_DELAYED_PIC_COUNT || cur->poc < h->last_pocs[i]){
            if(i)
                h->last_pocs[i-1] = cur->poc;
            break;
        } else if(i) {
            h->last_pocs[i-1]= h->last_pocs[i];
        }
    }
    out_of_order = MAX_DELAYED_PIC_COUNT - i;
    if(   cur->f.pict_type == AV_PICTURE_TYPE_B
       || (h->last_pocs[MAX_DELAYED_PIC_COUNT-2] > INT_MIN && h->last_pocs[MAX_DELAYED_PIC_COUNT-1] - h->last_pocs[MAX_DELAYED_PIC_COUNT-2] > 2))
        out_of_order = FFMAX(out_of_order, 1);
    if (out_of_order == MAX_DELAYED_PIC_COUNT) {
        av_log(h->avctx, AV_LOG_VERBOSE, "Invalid POC %d<%d\n", cur->poc, h->last_pocs[0]);
        for (i = 1; i < MAX_DELAYED_PIC_COUNT; i++)
            h->last_pocs[i] = INT_MIN;
        h->last_pocs[0] = cur->poc;
        cur->mmco_reset = 1;
    } else if(h->avctx->has_b_frames < out_of_order && !h->sps.bitstream_restriction_flag){
        av_log(h->avctx, AV_LOG_VERBOSE, "Increasing reorder buffer to %d\n", out_of_order);
        h->avctx->has_b_frames = out_of_order;
        h->low_delay = 0;
    }

    pics = 0;
    while (h->delayed_pic[pics])
        pics++;

    av_assert0(pics <= MAX_DELAYED_PIC_COUNT);

    h->delayed_pic[pics++] = cur;
    if (cur->reference == 0)
        cur->reference = DELAYED_PIC_REF;

    out     = h->delayed_pic[0];
    out_idx = 0;
    for (i = 1; h->delayed_pic[i] &&
                !h->delayed_pic[i]->f.key_frame &&
                !h->delayed_pic[i]->mmco_reset;
         i++)
        if (h->delayed_pic[i]->poc < out->poc) {
            out     = h->delayed_pic[i];
            out_idx = i;
        }
    if (h->avctx->has_b_frames == 0 &&
        (h->delayed_pic[0]->f.key_frame || h->delayed_pic[0]->mmco_reset))
        h->next_outputed_poc = INT_MIN;
    out_of_order = out->poc < h->next_outputed_poc;

    if (out_of_order || pics > h->avctx->has_b_frames) {
        out->reference &= ~DELAYED_PIC_REF;
        // for frame threading, the owner must be the second field's thread or
        // else the first thread can release the picture and reuse it unsafely
        for (i = out_idx; h->delayed_pic[i]; i++)
            h->delayed_pic[i] = h->delayed_pic[i + 1];
    }
    if (!out_of_order && pics > h->avctx->has_b_frames) {
        h->next_output_pic = out;
        if (out_idx == 0 && h->delayed_pic[0] && (h->delayed_pic[0]->f.key_frame || h->delayed_pic[0]->mmco_reset)) {
            h->next_outputed_poc = INT_MIN;
        } else
            h->next_outputed_poc = out->poc;
    } else {
        av_log(h->avctx, AV_LOG_DEBUG, "no picture %s\n", out_of_order ? "ooo" : "");
    }

    if (h->next_output_pic) {
        if (h->next_output_pic->recovered) {
            // We have reached an recovery point and all frames after it in
            // display order are "recovered".
            h->frame_recovered |= FRAME_RECOVERED_SEI;
        }
        h->next_output_pic->recovered |= !!(h->frame_recovered & FRAME_RECOVERED_SEI);
    }

    if (setup_finished && !h->avctx->hwaccel)
        ff_thread_finish_setup(h->avctx);
}

int ff_pred_weight_table(H264Context *h)
{
    int list, i;
    int luma_def, chroma_def;

    h->use_weight             = 0;
    h->use_weight_chroma      = 0;
    h->luma_log2_weight_denom = get_ue_golomb(&h->gb);
    if (h->sps.chroma_format_idc)
        h->chroma_log2_weight_denom = get_ue_golomb(&h->gb);
    luma_def   = 1 << h->luma_log2_weight_denom;
    chroma_def = 1 << h->chroma_log2_weight_denom;

    for (list = 0; list < 2; list++) {
        h->luma_weight_flag[list]   = 0;
        h->chroma_weight_flag[list] = 0;
        for (i = 0; i < h->ref_count[list]; i++) {
            int luma_weight_flag, chroma_weight_flag;