09.07.2022, 16:44
Hello,
I have some PAL SD videos captured from digital camera using Windows Media Player over FireWire. They are Type-2 AVIs (the audio stream is stored twice - once interleaved in the video, and once separately, where the interleaved stream is disabled). Here's a sample of ffprobe:
For some reason, the interleaved stream is at 48000 Hz (wrong!), but the real stream is correct at 32000 Hz. This shouldn't be a problem because the wrong stream is disabled anyway. When I encode with Hybrid using "passthrough all", I expect the streams to be preserved. However, it seems like instead, the second one gets resampled to 48000 Hz:
As you would expect, this resampling completely messes the audio when played back.
Out of curiosity, why does Hybrid extract the audio streams and them merge them back in? This sounds like an error-prone process.
Actually, even if you fix the "passthrough" issue, so both streams keep their sample rate, I think that would still break my case because when encoding the final video, Hybrid won't set the second stream as default/the first one as disabled. Would it be possible to just add audio "auto add (last)" the same way there is "auto add (first)"? This will be a nice trick for all Type-2 AVIs. I was planning to work around this issue by using the mkvmerge custom option "--audio-tracks 1" and select the second stream, but that fails since Hybrid already uses "--no-audio" due to the extraction mechanism above.
The reason why I can't just manually make these selections is because I am running an automated pipeline with zero user interaction.
My system:
- Windows 11
- Hybrid 2022.07.01.1
Thank you!
I have some PAL SD videos captured from digital camera using Windows Media Player over FireWire. They are Type-2 AVIs (the audio stream is stored twice - once interleaved in the video, and once separately, where the interleaved stream is disabled). Here's a sample of ffprobe:
Stream #0:0: Video: dvvideo, yuv420p, 720x576 [SAR 16:15 DAR 4:3], 25000 kb/s, 25 fps, 25 tbr, 25 tbn
Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Stream #0:2: Audio: pcm_s16le, 32000 Hz, stereo, s16, 1024 kb/sFor some reason, the interleaved stream is at 48000 Hz (wrong!), but the real stream is correct at 32000 Hz. This shouldn't be a problem because the wrong stream is disabled anyway. When I encode with Hybrid using "passthrough all", I expect the streams to be preserved. However, it seems like instead, the second one gets resampled to 48000 Hz:
Stream #0:0: Video: utvideo (ULY0 / 0x30594C55), yuv420p(tv, bt470bg/bt470bg/bt709), 720x576, SAR 16:15 DAR 4:3, 50 fps, 50 tbr, 1k tbn
Metadata:
ENCODER : Lavc59.25.100 utvideo
BPS : 117941433
DURATION : 00:00:52.040000000
NUMBER_OF_FRAMES: 2602
NUMBER_OF_BYTES : 767209028
_STATISTICS_WRITING_APP: mkvmerge v67.0.0 ('Under Stars') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2022-07-09 14:27:00
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s (default)
Metadata:
BPS : 1536016
DURATION : 00:00:34.757000000
NUMBER_OF_FRAMES: 869
NUMBER_OF_BYTES : 6673416
_STATISTICS_WRITING_APP: mkvmerge v67.0.0 ('Under Stars') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2022-07-09 14:27:00
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:2: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
Metadata:
BPS : 1535994
DURATION : 00:00:51.840000000
NUMBER_OF_FRAMES: 1296
NUMBER_OF_BYTES : 9953244
_STATISTICS_WRITING_APP: mkvmerge v67.0.0 ('Under Stars') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2022-07-09 14:27:00
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTESAs you would expect, this resampling completely messes the audio when played back.
Out of curiosity, why does Hybrid extract the audio streams and them merge them back in? This sounds like an error-prone process.
Actually, even if you fix the "passthrough" issue, so both streams keep their sample rate, I think that would still break my case because when encoding the final video, Hybrid won't set the second stream as default/the first one as disabled. Would it be possible to just add audio "auto add (last)" the same way there is "auto add (first)"? This will be a nice trick for all Type-2 AVIs. I was planning to work around this issue by using the mkvmerge custom option "--audio-tracks 1" and select the second stream, but that fails since Hybrid already uses "--no-audio" due to the extraction mechanism above.
The reason why I can't just manually make these selections is because I am running an automated pipeline with zero user interaction.
My system:
- Windows 11
- Hybrid 2022.07.01.1
Thank you!