On Wed, 2024-10-23 at 19:45 +0000, Shane Warren wrote: > I decided to start a new thread since I have done a lot of testing > and patching on qsv and vaapi transcoding since last week. > > First, I decided to try to use QSV decoding and QSV encoding, but I > noticed a53 captions were being stripped out, and I narrowed this > down to the qsv decoders not passing the a53 captions on. I noticed > there was a patch for SEI parsing for QSV decoders that was never > merged into mainline ffmpeg. The patchset can be seen here: > https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=&submitter=&state=&q=+Implement+SEI+parsing+for+QSV+decoders&archive=&delegate= > I applied that patchset up to v6 of the patch. I had to fix a lot of > API changes from that older version up to my mostly recent version > but after that patch, QSV decode -> QSV encode passed a53 captions > and they looked correct in my extensive testing (at least for h264). > > I'm trying to replace our use of nvidia cards and replace them with > intel cards for transcoding. We make use of overlays, so I was trying > to use overlay_qsv to allow: h264_qsv -> vpp_qsv=deinterlace,scale -> > overlay_qsv but a53 captions were getting slightly garbled. I then > tried a lot of combinations and a53 captions get garbled in all > these: > > 1. QSV decode -> vpp_qsv -> overlay_qsv -> h264_qsv = bad closed > captions > 2. QSV decode -> overlay_qsv -> h264_qsv = bad closed captions > 3. Software decode -> overlay_qsv -> h264_qsv = bad closed captions > 4. Software decode -> overlay -> h264_qsv = bad closed captions
Could you share your patch/clip/cmdline to me? I can help to check it. Thanks Fei > > I then decided apparently h264_qsv can mess up captions itself, but > strangely not if using qsv decoding. > > I then settled on: vaapi_h264 -> deinterlace_vaapi -> scale_vaapi -> > overaly_vaapi and a53 captions worked great and cpu usage (5-8%) was > the lowest of any overlay I've seen, which means it's almost entirely > in the gpu. > > Now I'm wondering if I should go back to using vaapi decoding and > encoding for everything, I had started out this project wanting to > use qsv since it in theory was the newest and had more features. > > Are there any downsides to using vaapi over qsv? I just want > something that works and produces good quality transcoding. > > Thanks, > Shane Warren > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://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 https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
