[vlc-devel] [PATCH 1/3] nvdec: always use opaque chroma as output

Steve Lhomme robux4 at ycbcr.xyz
Mon Mar 16 09:41:08 CET 2020


On 2020-03-16 9:33, Thomas Guillem wrote:
> 
> 
> On Mon, Mar 16, 2020, at 09:31, Steve Lhomme wrote:
>> I don't think it's a good idea.
>>
>> It forces a converter filter in the vout thread like this:
>> "A filter to adapt decoder NVD8 to display NV12 is needed"
>>
>> Converter filters consume resources in the vout thread that is time
>> critical to get the proper display timing. It sometimes causes frames to
>> be late or even skipped because the conversion is too long.
>>
>> When the conversion is done by the decoder the vout thread has more
>> liberty to drop frames earlier and less often.
> 
> But this is what is done on all other HW decoders, non ?

No, for the others the display system can usually handle it without 
conversion. CUDA is not handled by any display systems. Even the OpenGL 
interop module does a copy into another buffer so it can be used to display.

>>
>> I understand the opaque chroma is currently used first and always work
>> (with the converter filter) but IMO it should probably be the other way
>> around. Outputting CUDA surfaces will only make sense when/if we have
>> CUDA filters (other than the GPU to CPU converter).
>>
>> We could also move the converter filter outside of the vout thread into
>> the decoder (when it pushes pictures for example) to avoid this but
>> that's a different subject. I don't think we'll do that in 4.0.
>>
>> On 2020-03-13 17:19, quentin.chateau at deepskycorp.com wrote:
>>> From: Quentin Chateau <quentin.chateau at deepskycorp.com>
>>>
>>> MapSurfaceChroma now maps cudaChroma to opaque chromas
>>> ---
>>>    modules/hw/nvdec/nvdec.c     | 95 +++---------------------------------
>>>    modules/hw/nvdec/nvdec_fmt.h |  9 ----
>>>    modules/hw/nvdec/nvdec_gl.c  |  3 --
>>>    3 files changed, 6 insertions(+), 101 deletions(-)
>>>
>>> diff --git a/modules/hw/nvdec/nvdec.c b/modules/hw/nvdec/nvdec.c
>>> index 162330788f..4fc70a5f5c 100644
>>> --- a/modules/hw/nvdec/nvdec.c
>>> +++ b/modules/hw/nvdec/nvdec.c
>>> @@ -113,14 +113,14 @@ static vlc_fourcc_t MapSurfaceChroma(cudaVideoChromaFormat chroma, unsigned bitD
>>>        switch (chroma) {
>>>            case cudaVideoChromaFormat_420:
>>>                if (bitDepth <= 8)
>>> -                return VLC_CODEC_NV12;
>>> +                return VLC_CODEC_NVDEC_OPAQUE;
>>>                if (bitDepth <= 10)
>>> -                return VLC_CODEC_P010;
>>> -            return VLC_CODEC_P016;
>>> +                return VLC_CODEC_NVDEC_OPAQUE_10B;
>>> +            return VLC_CODEC_NVDEC_OPAQUE_16B;
>>>            case cudaVideoChromaFormat_444:
>>>                if (bitDepth <= 8)
>>> -                return VLC_CODEC_I444;
>>> -            return VLC_CODEC_I444_16L;
>>> +                return VLC_CODEC_NVDEC_OPAQUE_444;
>>> +            return VLC_CODEC_NVDEC_OPAQUE_444_16B;
>>>            default:
>>>                return 0;
>>>        }
>>> @@ -131,17 +131,12 @@ static cudaVideoSurfaceFormat MapSurfaceFmt(int i_vlc_fourcc)
>>>        switch (i_vlc_fourcc) {
>>>            case VLC_CODEC_NVDEC_OPAQUE_10B:
>>>            case VLC_CODEC_NVDEC_OPAQUE_16B:
>>> -        case VLC_CODEC_P010:
>>> -        case VLC_CODEC_P016:
>>>                return cudaVideoSurfaceFormat_P016;
>>>            case VLC_CODEC_NVDEC_OPAQUE:
>>> -        case VLC_CODEC_NV12:
>>>                return cudaVideoSurfaceFormat_NV12;
>>>            case VLC_CODEC_NVDEC_OPAQUE_444:
>>> -        case VLC_CODEC_I444:
>>>                return cudaVideoSurfaceFormat_YUV444;
>>>            case VLC_CODEC_NVDEC_OPAQUE_444_16B:
>>> -        case VLC_CODEC_I444_16L:
>>>                 return cudaVideoSurfaceFormat_YUV444_16Bit;
>>>            default:             vlc_assert_unreachable();
>>>        }
>>> @@ -151,15 +146,6 @@ static int CUtoFMT(video_format_t *fmt, const CUVIDEOFORMAT *p_format)
>>>    {
>>>        // bit depth and chroma
>>>        unsigned int i_bpp = p_format->bit_depth_luma_minus8 + 8;
>>> -    vlc_fourcc_t i_chroma;
>>> -    if (is_nvdec_opaque(fmt->i_chroma))
>>> -        i_chroma = fmt->i_chroma;
>>> -    else
>>> -        i_chroma = MapSurfaceChroma(p_format->chroma_format, i_bpp);
>>> -    if (i_chroma == 0)
>>> -        return VLC_EGENERIC;
>>> -
>>> -    fmt->i_chroma = i_chroma;
>>>        // use the real padded size when we know it fmt->i_width = p_format->coded_width;
>>>        fmt->i_height = p_format->coded_height;
>>>        fmt->i_x_offset = p_format->display_area.left;
>>> @@ -179,8 +165,6 @@ static int CUDAAPI HandleVideoSequence(void *p_opaque, CUVIDEOFORMAT *p_format)
>>>        nvdec_ctx_t *p_sys = p_dec->p_sys;
>>>        int ret;
>>>    
>>> -    if ( is_nvdec_opaque(p_dec->fmt_out.video.i_chroma) )
>>> -    {
>>>            for (size_t i=0; i < ARRAY_SIZE(p_sys->outputDevicePtr); i++)
>>>            {
>>>                CALL_CUDA_DEC(cuMemFree, p_sys->outputDevicePtr[i]);
>>> @@ -192,7 +176,6 @@ static int CUDAAPI HandleVideoSequence(void *p_opaque, CUVIDEOFORMAT *p_format)
>>>                picture_pool_Release(p_sys->out_pool);
>>>                p_sys->out_pool = NULL;
>>>            }
>>> -    }
>>>    
>>>        // update vlc's output format using NVDEC parser's output
>>>        ret = CUtoFMT(&p_dec->fmt_out.video, p_format);
>>> @@ -231,8 +214,6 @@ static int CUDAAPI HandleVideoSequence(void *p_opaque, CUVIDEOFORMAT *p_format)
>>>            goto error;
>>>    
>>>        // ensure the output surfaces have the same pitch so copies can work properly
>>> -    if ( is_nvdec_opaque(p_dec->fmt_out.video.i_chroma) )
>>> -    {
>>>            // get the real decoder pitch
>>>            CUdeviceptr frameDevicePtr = 0;
>>>            CUVIDPROCPARAMS params = {
>>> @@ -298,8 +279,6 @@ clean_pics:
>>>                goto error;
>>>    
>>>            p_sys->out_pool = picture_pool_New( ARRAY_SIZE(p_sys->outputDevicePtr), pics );
>>> -    }
>>> -
>>>        p_sys->decoderHeight = p_format->coded_height;
>>>    
>>>        CALL_CUDA_DEC(cuCtxPopCurrent, NULL);
>>> @@ -360,8 +339,6 @@ static int CUDAAPI HandlePictureDisplay(void *p_opaque, CUVIDPARSERDISPINFO *p_d
>>>        };
>>>        int result;
>>>    
>>> -    if ( is_nvdec_opaque(p_dec->fmt_out.video.i_chroma) )
>>> -    {
>>>            p_pic = picture_pool_Wait(p_sys->out_pool);
>>>            if (unlikely(p_pic == NULL))
>>>                return 0;
>>> @@ -450,49 +427,6 @@ static int CUDAAPI HandlePictureDisplay(void *p_opaque, CUVIDPARSERDISPINFO *p_d
>>>            }
>>>            p_pic->context = &picctx->ctx;
>>>            vlc_video_context_Hold(picctx->ctx.vctx);
>>> -    }
>>> -    else
>>> -    {
>>> -        p_pic = decoder_NewPicture(p_dec);
>>> -        if (unlikely(p_pic == NULL))
>>> -            return 0;
>>> -
>>> -        result = CALL_CUDA_DEC(cuCtxPushCurrent, p_sys->cuCtx);
>>> -        if (unlikely(result != VLC_SUCCESS))
>>> -        {
>>> -            picture_Release(p_pic);
>>> -            return 0;
>>> -        }
>>> -
>>> -        unsigned int i_pitch;
>>> -
>>> -        // Map decoded frame to a device pointer
>>> -        result = CALL_CUVID( cuvidMapVideoFrame, p_sys->cudecoder, p_dispinfo->picture_index,
>>> -                            &frameDevicePtr, &i_pitch, &params );
>>> -        if (result != VLC_SUCCESS)
>>> -            goto error;
>>> -
>>> -        // Copy decoded frame into a new VLC picture
>>> -        size_t srcY = 0;
>>> -        for (int i_plane = 0; i_plane < p_pic->i_planes; i_plane++) {
>>> -            plane_t plane = p_pic->p[i_plane];
>>> -            CUDA_MEMCPY2D cu_cpy = {
>>> -                .srcMemoryType  = CU_MEMORYTYPE_DEVICE,
>>> -                .srcDevice      = frameDevicePtr,
>>> -                .srcY           = srcY,
>>> -                .srcPitch       = i_pitch,
>>> -                .dstMemoryType  = CU_MEMORYTYPE_HOST,
>>> -                .dstHost        = plane.p_pixels,
>>> -                .dstPitch       = plane.i_pitch,
>>> -                .WidthInBytes   = i_pitch,
>>> -                .Height         = plane.i_visible_lines,
>>> -            };
>>> -            result = CALL_CUDA_DEC(cuMemcpy2D, &cu_cpy);
>>> -            if (result != VLC_SUCCESS)
>>> -                goto error;
>>> -            srcY += p_sys->decoderHeight;
>>> -        }
>>> -    }
>>>    
>>>        // Release surface on GPU
>>>        result = CALL_CUVID(cuvidUnmapVideoFrame, p_sys->cudecoder, frameDevicePtr);
>>> @@ -932,25 +866,8 @@ static int OpenDecoder(vlc_object_t *p_this)
>>>            goto error;
>>>        }
>>>    
>>> -    vlc_fourcc_t output_chromas[3];
>>> +    vlc_fourcc_t output_chromas[2];
>>>        size_t chroma_idx = 0;
>>> -    if (cudaChroma == cudaVideoChromaFormat_420)
>>> -    {
>>> -        if (i_depth_luma >= 16)
>>> -            output_chromas[chroma_idx++] = VLC_CODEC_NVDEC_OPAQUE_16B;
>>> -        else if (i_depth_luma > 8)
>>> -            output_chromas[chroma_idx++] = VLC_CODEC_NVDEC_OPAQUE_10B;
>>> -        else
>>> -            output_chromas[chroma_idx++] = VLC_CODEC_NVDEC_OPAQUE;
>>> -    }
>>> -    else if (cudaChroma == cudaVideoChromaFormat_444)
>>> -    {
>>> -        if (i_depth_luma > 8)
>>> -            output_chromas[chroma_idx++] = VLC_CODEC_NVDEC_OPAQUE_444_16B;
>>> -        else
>>> -            output_chromas[chroma_idx++] = VLC_CODEC_NVDEC_OPAQUE_444;
>>> -    }
>>> -
>>>        output_chromas[chroma_idx++] = MapSurfaceChroma(cudaChroma, i_depth_luma);
>>>        output_chromas[chroma_idx++] = 0;
>>>    
>>> diff --git a/modules/hw/nvdec/nvdec_fmt.h b/modules/hw/nvdec/nvdec_fmt.h
>>> index 25784cca6d..d84672d8fb 100644
>>> --- a/modules/hw/nvdec/nvdec_fmt.h
>>> +++ b/modules/hw/nvdec/nvdec_fmt.h
>>> @@ -51,15 +51,6 @@ static inline int CudaCheckErr(vlc_object_t *obj, CudaFunctions *cudaFunctions,
>>>        return VLC_SUCCESS;
>>>    }
>>>    
>>> -static inline bool is_nvdec_opaque(vlc_fourcc_t fourcc)
>>> -{
>>> -    return fourcc == VLC_CODEC_NVDEC_OPAQUE ||
>>> -           fourcc == VLC_CODEC_NVDEC_OPAQUE_10B ||
>>> -           fourcc == VLC_CODEC_NVDEC_OPAQUE_16B ||
>>> -           fourcc == VLC_CODEC_NVDEC_OPAQUE_444 ||
>>> -           fourcc == VLC_CODEC_NVDEC_OPAQUE_444_16B;
>>> -}
>>> -
>>>    /* for VLC_CODEC_NVDEC_OPAQUE / VLC_CODEC_NVDEC_OPAQUE_16B */
>>>    typedef struct
>>>    {
>>> diff --git a/modules/hw/nvdec/nvdec_gl.c b/modules/hw/nvdec/nvdec_gl.c
>>> index 137e730028..62a503a8e8 100644
>>> --- a/modules/hw/nvdec/nvdec_gl.c
>>> +++ b/modules/hw/nvdec/nvdec_gl.c
>>> @@ -156,9 +156,6 @@ static void Close(vlc_object_t *obj)
>>>    static int Open(vlc_object_t *obj)
>>>    {
>>>        struct vlc_gl_interop *interop = (void *) obj;
>>> -    if (!is_nvdec_opaque(interop->fmt.i_chroma))
>>> -        return VLC_EGENERIC;
>>> -
>>>        vlc_decoder_device *device = vlc_video_context_HoldDevice(interop->vctx);
>>>        if (device == NULL || device->type != VLC_DECODER_DEVICE_NVDEC)
>>>            return VLC_EGENERIC;
>>> -- 
>>> 2.17.1
>>>
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