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_dsputil_init(&h->dsp, 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 */
    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;

    flush_change(h);

    return 0;
}

Unknown