[FFmpeg-devel] [PATCH 2/2] ffmpeg: Add cuvid hwaccel support

[Andrey Turkin]

2016-06-05 21:58 GMT+03:00 Timo Rothenpieler <timo at rothenpieler.org>:


> +    /* check if the decoder supports CUVID and the output only goes to
> this stream */
> +    if (ist->nb_filters || ist->hwaccel_id != HWACCEL_CUVID || !ist->dec
> || !ist->dec->pix_fmts)
> +        goto cancel;
> +    for (pix_fmt = ist->dec->pix_fmts; *pix_fmt != AV_PIX_FMT_NONE;
> pix_fmt++)
> +        if (*pix_fmt == AV_PIX_FMT_CUDA)
> +            break;
> +    if (*pix_fmt == AV_PIX_FMT_NONE)
> +        goto cancel;
> +
> +    for (i = 0; i < nb_output_streams; i++)
> +        if (output_streams[i] != ost && output_streams[i]->source_index
> == ost->source_index)
> +            goto cancel;
>

Is it possible to enhance this to support 1-to-N transcoding (usecase
solved by NVidia's patch with nvresize)? One can do the same with complex
filtergraph with several scale_npp instances. This seems like a bit of
over-restriction.

+    err = cuInit(0);
> +    if (err != CUDA_SUCCESS) {
> +        av_log(NULL, AV_LOG_ERROR, "Could not initialize the CUDA driver
> API\n");
> +        ret = AVERROR_UNKNOWN;
> +        goto error;
> +    }
> +
> +    err = cuDeviceGet(&device, 0); ///TODO: Make device index configurable
> +    if (err != CUDA_SUCCESS) {
> +        av_log(NULL, AV_LOG_ERROR, "Could not get the device number
> %d\n", 0);
> +        ret = AVERROR_UNKNOWN;
> +        goto error;
> +    }
> +
> +    err = cuCtxCreate(&cuda_ctx, CU_CTX_SCHED_BLOCKING_SYNC, device);
> +    if (err != CUDA_SUCCESS) {
> +        av_log(NULL, AV_LOG_ERROR, "Error creating a CUDA context\n");
> +        ret = AVERROR_UNKNOWN;
> +        goto error;
> +    }
> +
> +    device_ctx = (AVHWDeviceContext*)hw_device_ctx->data;
> +    device_ctx->free = cuvid_ctx_free;
> +
> +    device_hwctx = device_ctx->hwctx;
> +    device_hwctx->cuda_ctx = cuda_ctx;
> +
> +    err = cuCtxPopCurrent(&dummy);
> +    if (err != CUDA_SUCCESS) {
> +        av_log(NULL, AV_LOG_ERROR, "cuCtxPopCurrent failed\n");
> +        ret = AVERROR_UNKNOWN;
> +        goto error;
> +    }
> +


It begs to merge in device_create functionality from libav