[FFmpeg-user] Intel QSV Transcoding Stops on Resolution Change

[Wang, Fei W]

> -----Original Message-----
> From: ffmpeg-user <ffmpeg-user-bounces at ffmpeg.org> On Behalf Of Shane
> Warren
> Sent: Friday, August 30, 2024 10:23 PM
> To: ffmpeg-user at ffmpeg.org
> Subject: [FFmpeg-user] Intel QSV Transcoding Stops on Resolution
> Change
> 
> I am transcoding live video using intel flex 140 cards, and the video
> mostly stays
> one resolution/framerate but sometimes ads come in that are in
> different
> resolutions, and that either crashes ffmpeg (in libmfx) or stops
> ffmpeg.
> 
> For example, an input stream starts out at 1280x720p at 60 then
> eventually
> changes 1920x1080i at 30 and then back to 1280x720p at 60.
> 
> I've tried using many ways to make FFmpeg survive the resolution
> change:
> - software decoding, then vpp_qsv (for deinterlacing and scaling),
> then
> h264_qsv... this crashes inside libmfx if a resolution change happens
> - hardware decoding using vaapi, then hwmap=derive_device=qsv, then
> vpp_qsv
> (for deinterlacing and scaling), then h264_qsv this just stops with
> this message:
> 
> [graph 0 input from stream 0:0 @ 0x561180fc1ac0] w:1920 h:1080
> pixfmt:vaapi
> tb:1/90000 fr:60000/1001 sar:1/1
> [scaler_out_0_0 @ 0x561181e57ac0] w:1280 h:720 flags:'' interl:0
> [auto_scale_0 @ 0x561181430e80] w:iw h:ih flags:'' interl:0 [format @
> 0x561181e6dd80] auto-inserting filter 'auto_scale_0' between the
> filter
> 'scaler_out_0_0' and the filter 'format'
> Impossible to convert between the formats supported by the filter
> 'scaler_out_0_0' and the filter 'auto_scale_0'
> 
> - I also tried software decoding, then using vaapi deinterlacing, and
> vaapi scaling,
> this exits with the same error as above.
> 
> - I should note that I can't use qsv decoding because I noticed qsv
> decoding strips
> off a53 captions, which I need.
> 
> Any ideas on what combination of decoding, deinterlacing/scaling, and
> encoding I
> can use with these flex 140 cards that can handle a resolution change
> on the
> input.
> 
> Here is my ffmpeg command line when I'm using vaapi to decode and qsv
> to
> encode:

You may need to add "-noautoscale" option in your cmdline. While
current ffmpeg-qsv have a surface alignment issue when derive from
vaapi surface in some particular resolution. If your cmd still fail,
you can try this patch:
https://github.com/intel-media-ci/ffmpeg/pull/765

Thanks
Fei

> 
> ffmpeg -y -threads 2 -nostats -nostdin -loglevel verbose -progress
> pipe:1 -
> probesize 5M -filter_threads 4 -threads 2 -fflags +genpts -fflags
> discardcorrupt -
> hwaccel_output_format vaapi \ -qsv_device /dev/dri/card1 -
> init_hw_device
> qsv=hw -filter_hw_device hw -hwaccel vaapi \ -i
> "udp://@225.105.0.28:10102??fifo_size=2146880&buffer_size=65535&timeo
> ut=
> 800000" \ -threads 2 -c:a:0 ac3 -dialnorm -28 -threads 2 -ac:a:0 6 -
> ar:a:0 48000 -
> b:a:0 384k -flush_packets 0 \ -filter_complex
> "[0:v:0]fps=60000/1001,hwmap=derive_device=qsv,vpp_qsv=deinterlace=2:
> w=1
> 280:h=720[vout]" \ -map "[vout]" -map "0:a:0" \ -c:v h264_qsv -b:v
> 3000k -
> minrate:v 3000k -maxrate:v 3000k -bufsize:v 6000k -preset veryfast -
> scenario
> livestreaming -strict_gop 1 -forced_idr 1 -profile:v high -level:v
> 4.2 -bf:v 0 -g:v 30
> \ -f mpegts -muxrate 3863560 -pes_payload_size 1528
> "udp://@225.105.0.35:10102?pkt_size=1316&fifo_size=90000&bitrate=3863
> 560
> &burst_bits=10528&ttl=64"
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