Function commit_bitstream_and_slice_buffer

libavcodec/dxva2_h264.c:259–354

}

static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
                                             DXVA2_DecodeBufferDesc *bs,
                                             DXVA2_DecodeBufferDesc *sc)
{
    const H264Context *h = avctx->priv_data;
    const MpegEncContext *s = &h->s;
    const unsigned mb_count = s->mb_width * s->mb_height;
    struct dxva_context *ctx = avctx->hwaccel_context;
    const Picture *current_picture = h->s.current_picture_ptr;
    struct dxva2_picture_context *ctx_pic = current_picture->hwaccel_picture_private;
    DXVA_Slice_H264_Short *slice = NULL;
    uint8_t  *dxva_data, *current, *end;
    unsigned dxva_size;
    void     *slice_data;
    unsigned slice_size;
    unsigned padding;
    unsigned i;

    /* Create an annex B bitstream buffer with only slice NAL and finalize slice */
    if (FAILED(IDirectXVideoDecoder_GetBuffer(ctx->decoder,
                                               DXVA2_BitStreamDateBufferType,
                                               &dxva_data, &dxva_size)))
        return -1;
    current = dxva_data;
    end = dxva_data + dxva_size;

    for (i = 0; i < ctx_pic->slice_count; i++) {
        static const uint8_t start_code[] = { 0, 0, 1 };
        static const unsigned start_code_size = sizeof(start_code);
        unsigned position, size;

        assert(offsetof(DXVA_Slice_H264_Short, BSNALunitDataLocation) ==
               offsetof(DXVA_Slice_H264_Long,  BSNALunitDataLocation));
        assert(offsetof(DXVA_Slice_H264_Short, SliceBytesInBuffer) ==
               offsetof(DXVA_Slice_H264_Long,  SliceBytesInBuffer));

        if (is_slice_short(ctx))
            slice = &ctx_pic->slice_short[i];
        else
            slice = (DXVA_Slice_H264_Short*)&ctx_pic->slice_long[i];

        position = slice->BSNALunitDataLocation;
        size     = slice->SliceBytesInBuffer;
        if (start_code_size + size > end - current) {
            av_log(avctx, AV_LOG_ERROR, "Failed to build bitstream");
            break;
        }

        slice->BSNALunitDataLocation = current - dxva_data;
        slice->SliceBytesInBuffer    = start_code_size + size;

        if (!is_slice_short(ctx)) {
            DXVA_Slice_H264_Long *slice_long = (DXVA_Slice_H264_Long*)slice;
            if (i < ctx_pic->slice_count - 1)
                slice_long->NumMbsForSlice =
                    slice_long[1].first_mb_in_slice - slice_long[0].first_mb_in_slice;
            else
                slice_long->NumMbsForSlice = mb_count - slice_long->first_mb_in_slice;