Function vaapi_encode_make_row_slice

libavcodec/vaapi_encode.c:186–239

}

static int vaapi_encode_make_row_slice(AVCodecContext *avctx,
                                       VAAPIEncodePicture *pic)
{
    VAAPIEncodeContext *ctx = avctx->priv_data;
    VAAPIEncodeSlice *slice;
    int i, rounding;

    for (i = 0; i < pic->nb_slices; i++)
        pic->slices[i].row_size = ctx->slice_size;

    rounding = ctx->slice_block_rows - ctx->nb_slices * ctx->slice_size;
    if (rounding > 0) {
        // Place rounding error at top and bottom of frame.
        av_assert0(rounding < pic->nb_slices);
        // Some Intel drivers contain a bug where the encoder will fail
        // if the last slice is smaller than the one before it.  Since
        // that's straightforward to avoid here, just do so.
        if (rounding <= 2) {
            for (i = 0; i < rounding; i++)
                ++pic->slices[i].row_size;
        } else {
            for (i = 0; i < (rounding + 1) / 2; i++)
                ++pic->slices[pic->nb_slices - i - 1].row_size;
            for (i = 0; i < rounding / 2; i++)
                ++pic->slices[i].row_size;
        }
    } else if (rounding < 0) {
        // Remove rounding error from last slice only.
        av_assert0(rounding < ctx->slice_size);
        pic->slices[pic->nb_slices - 1].row_size += rounding;
    }

    for (i = 0; i < pic->nb_slices; i++) {
        slice = &pic->slices[i];
        slice->index = i;
        if (i == 0) {
            slice->row_start   = 0;
            slice->block_start = 0;
        } else {
            const VAAPIEncodeSlice *prev = &pic->slices[i - 1];
            slice->row_start   = prev->row_start   + prev->row_size;
            slice->block_start = prev->block_start + prev->block_size;
        }
        slice->block_size  = slice->row_size * ctx->slice_block_cols;

        av_log(avctx, AV_LOG_DEBUG, "Slice %d: %d-%d (%d rows), "
               "%d-%d (%d blocks).\n", i, slice->row_start,
               slice->row_start + slice->row_size - 1, slice->row_size,
               slice->block_start, slice->block_start + slice->block_size - 1,
               slice->block_size);
    }

    return 0;
}

static int vaapi_encode_make_tile_slice(AVCodecContext *avctx,
                                        VAAPIEncodePicture *pic)