Re: [FFmpeg-user] VAAPI Decoding/Encoding with C code
On 02/12/16 14:05, Victor dMdB wrote: > Thanks for the response Mark! > > I might be misreading the source code, but for decoding, doesn't > vaapi_decode_init > do all the heavy lifting? > It seems to already call the functions and sets the variables you > mentioned. > > So might the code be just: > > avcodec_open2(codecCtx, codec,NULL); > vaapi_decode_init(codecCtx); vaapi_decode_init() is a function inside the ffmpeg utility, not any of the libraries. You need to implement what it does in your own application. You can copy/adapt the relevant code directly from the ffmpeg utility into your application if you want (assuming you comply with the licence terms). - Mark > On Fri, 2 Dec 2016, at 09:03 PM, Mark Thompson wrote: >> On 02/12/16 10:57, Victor dMdB wrote: >>> I was wondering if there were any examples of implementations with >>> avformatcontext? >>> >>> I've looked at the source of ffmpeg vaapi implementation: >>> https://www.ffmpeg.org/doxygen/trunk/ffmpeg__vaapi_8c_source.html >>> >>> and there is a reference to the cli values here >>> https://ffmpeg.org/pipermail/ffmpeg-user/2016-May/032153.html >>> >>> But I'm not really sure how one actually implements the it within either >>> decoding or encoding pipeline? >> >> Start by making an hwdevice. This can be done with >> av_hwdevice_ctx_create(), or if you already have a VADisplay (for >> example, to do stuff in X via DRI[23]) you can use >> av_hwdevice_ctx_alloc() followed by av_hwdevice_ctx_init(). >> >> For a decoder: >> >> Make the decoder as you normally would for software. You must set an >> AVCodecContext.get_format callback. >> Start feeding data to the decoder. >> Once enough there is enough data to determine the output format, the >> get_format callback will be called (this will always happen before any >> output is generated). >> The callback has a set of possible formats to use, this will contain >> AV_PIX_FMT_VAAPI if your stream is supported (note that not all streams >> are supported for a given decoder - for H.264 the hwaccel only supports >> YUV 4:2:0 in 8-bit depth). >> Make an hwframe context for the output frames and a struct vaapi_context >> containing a decode context*. See ffmpeg_vaapi.c:vaapi_decode_init() and >> its callees for this part. >> Attach your new hwframe context (AVCodecContext.hw_frames_ctx) and decode >> context (AVCodecContext.hwaccel_context) to the decoder. >> Once you return from the callback, decoding continues and will give you >> AV_PIX_FMT_VAAPI frames. >> If you need the output frames in normal memory rather than GPU memory, >> you can copy them back with av_hwframe_transfer_data(). >> >> For an encoder: >> >> Find an hwframe context to use as the encoder input. For a transcode >> case this can be the one from the decoder above, or it could be output >> from a filter like scale_vaapi. If only have frames in normal memory, >> you need to make a new one here. >> Make the encoder as you normally would (you'll need to get the codec by >> name (like "h264_vaapi"), because it will not choose it by default with >> just the ID), and set AVCodecContext.hw_frames_ctx with your hwframe >> context. >> Now feed the encoder with the AV_PIX_FMT_VAAPI frames from your hwframe >> context. >> If you only have input frames in normal memory, you will need to upload >> them to GPU memory in the hwframe context with av_hwframe_transfer_data() >> before giving them to the encoder. >> >> >> - Mark >> >> >> * It is intended that struct vaapi_context will be deprecated completely >> soon, and this part will not be required (lavc will handle that context >> creation). ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] VAAPI Decoding/Encoding with C code
Thanks for the response Mark! I might be misreading the source code, but for decoding, doesn't vaapi_decode_init do all the heavy lifting? It seems to already call the functions and sets the variables you mentioned. So might the code be just: avcodec_open2(codecCtx, codec,NULL); vaapi_decode_init(codecCtx); On Fri, 2 Dec 2016, at 09:03 PM, Mark Thompson wrote: > On 02/12/16 10:57, Victor dMdB wrote: > > I was wondering if there were any examples of implementations with > > avformatcontext? > > > > I've looked at the source of ffmpeg vaapi implementation: > > https://www.ffmpeg.org/doxygen/trunk/ffmpeg__vaapi_8c_source.html > > > > and there is a reference to the cli values here > > https://ffmpeg.org/pipermail/ffmpeg-user/2016-May/032153.html > > > > But I'm not really sure how one actually implements the it within either > > decoding or encoding pipeline? > > Start by making an hwdevice. This can be done with > av_hwdevice_ctx_create(), or if you already have a VADisplay (for > example, to do stuff in X via DRI[23]) you can use > av_hwdevice_ctx_alloc() followed by av_hwdevice_ctx_init(). > > For a decoder: > > Make the decoder as you normally would for software. You must set an > AVCodecContext.get_format callback. > Start feeding data to the decoder. > Once enough there is enough data to determine the output format, the > get_format callback will be called (this will always happen before any > output is generated). > The callback has a set of possible formats to use, this will contain > AV_PIX_FMT_VAAPI if your stream is supported (note that not all streams > are supported for a given decoder - for H.264 the hwaccel only supports > YUV 4:2:0 in 8-bit depth). > Make an hwframe context for the output frames and a struct vaapi_context > containing a decode context*. See ffmpeg_vaapi.c:vaapi_decode_init() and > its callees for this part. > Attach your new hwframe context (AVCodecContext.hw_frames_ctx) and decode > context (AVCodecContext.hwaccel_context) to the decoder. > Once you return from the callback, decoding continues and will give you > AV_PIX_FMT_VAAPI frames. > If you need the output frames in normal memory rather than GPU memory, > you can copy them back with av_hwframe_transfer_data(). > > For an encoder: > > Find an hwframe context to use as the encoder input. For a transcode > case this can be the one from the decoder above, or it could be output > from a filter like scale_vaapi. If only have frames in normal memory, > you need to make a new one here. > Make the encoder as you normally would (you'll need to get the codec by > name (like "h264_vaapi"), because it will not choose it by default with > just the ID), and set AVCodecContext.hw_frames_ctx with your hwframe > context. > Now feed the encoder with the AV_PIX_FMT_VAAPI frames from your hwframe > context. > If you only have input frames in normal memory, you will need to upload > them to GPU memory in the hwframe context with av_hwframe_transfer_data() > before giving them to the encoder. > > > - Mark > > > * It is intended that struct vaapi_context will be deprecated completely > soon, and this part will not be required (lavc will handle that context > creation). > > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] VAAPI Decoding/Encoding with C code
On 02/12/16 10:57, Victor dMdB wrote: > I was wondering if there were any examples of implementations with > avformatcontext? > > I've looked at the source of ffmpeg vaapi implementation: > https://www.ffmpeg.org/doxygen/trunk/ffmpeg__vaapi_8c_source.html > > and there is a reference to the cli values here > https://ffmpeg.org/pipermail/ffmpeg-user/2016-May/032153.html > > But I'm not really sure how one actually implements the it within either > decoding or encoding pipeline? Start by making an hwdevice. This can be done with av_hwdevice_ctx_create(), or if you already have a VADisplay (for example, to do stuff in X via DRI[23]) you can use av_hwdevice_ctx_alloc() followed by av_hwdevice_ctx_init(). For a decoder: Make the decoder as you normally would for software. You must set an AVCodecContext.get_format callback. Start feeding data to the decoder. Once enough there is enough data to determine the output format, the get_format callback will be called (this will always happen before any output is generated). The callback has a set of possible formats to use, this will contain AV_PIX_FMT_VAAPI if your stream is supported (note that not all streams are supported for a given decoder - for H.264 the hwaccel only supports YUV 4:2:0 in 8-bit depth). Make an hwframe context for the output frames and a struct vaapi_context containing a decode context*. See ffmpeg_vaapi.c:vaapi_decode_init() and its callees for this part. Attach your new hwframe context (AVCodecContext.hw_frames_ctx) and decode context (AVCodecContext.hwaccel_context) to the decoder. Once you return from the callback, decoding continues and will give you AV_PIX_FMT_VAAPI frames. If you need the output frames in normal memory rather than GPU memory, you can copy them back with av_hwframe_transfer_data(). For an encoder: Find an hwframe context to use as the encoder input. For a transcode case this can be the one from the decoder above, or it could be output from a filter like scale_vaapi. If only have frames in normal memory, you need to make a new one here. Make the encoder as you normally would (you'll need to get the codec by name (like "h264_vaapi"), because it will not choose it by default with just the ID), and set AVCodecContext.hw_frames_ctx with your hwframe context. Now feed the encoder with the AV_PIX_FMT_VAAPI frames from your hwframe context. If you only have input frames in normal memory, you will need to upload them to GPU memory in the hwframe context with av_hwframe_transfer_data() before giving them to the encoder. - Mark * It is intended that struct vaapi_context will be deprecated completely soon, and this part will not be required (lavc will handle that context creation). ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] VAAPI Decoding/Encoding with C code
I was wondering if there were any examples of implementations with avformatcontext? I've looked at the source of ffmpeg vaapi implementation: https://www.ffmpeg.org/doxygen/trunk/ffmpeg__vaapi_8c_source.html and there is a reference to the cli values here https://ffmpeg.org/pipermail/ffmpeg-user/2016-May/032153.html But I'm not really sure how one actually implements the it within either decoding or encoding pipeline? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
