Function ff_decode_get_hw_frames_ctx

libavcodec/decode.c:1050–1099

}

int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
                                enum AVHWDeviceType dev_type)
{
    AVHWDeviceContext *device_ctx;
    AVHWFramesContext *frames_ctx;
    int ret;

    if (!avctx->hwaccel)
        return AVERROR(ENOSYS);

    if (avctx->hw_frames_ctx)
        return 0;
    if (!avctx->hw_device_ctx) {
        av_log(avctx, AV_LOG_ERROR, "A hardware frames or device context is "
                "required for hardware accelerated decoding.\n");
        return AVERROR(EINVAL);
    }

    device_ctx = (AVHWDeviceContext *)avctx->hw_device_ctx->data;
    if (device_ctx->type != dev_type) {
        av_log(avctx, AV_LOG_ERROR, "Device type %s expected for hardware "
               "decoding, but got %s.\n", av_hwdevice_get_type_name(dev_type),
               av_hwdevice_get_type_name(device_ctx->type));
        return AVERROR(EINVAL);
    }

    ret = avcodec_get_hw_frames_parameters(avctx,
                                           avctx->hw_device_ctx,
                                           avctx->hwaccel->pix_fmt,
                                           &avctx->hw_frames_ctx);
    if (ret < 0)
        return ret;

    frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;


    if (frames_ctx->initial_pool_size) {
        // We guarantee 4 base work surfaces. The function above guarantees 1
        // (the absolute minimum), so add the missing count.
        frames_ctx->initial_pool_size += 3;
    }

    ret = av_hwframe_ctx_init(avctx->hw_frames_ctx);
    if (ret < 0) {
        av_buffer_unref(&avctx->hw_frames_ctx);
        return ret;
    }

    return 0;
}

int avcodec_get_hw_frames_parameters(AVCodecContext *avctx,
                                     AVBufferRef *device_ref,