For supported sample rates other than 48k (i.e. 8k, 12k, 16k, 24k), OggOpusWriter generates an incorrectly reported duration, which causes bizarre behaviors depending on the audio player.
This generates left-right-demo-5s.wav.opus with an incorrect duration (ffmpeg reports 1.26s; opusinfo reports 2.149s), which will confuse various tools and audio players (e.g. VLC and Totem cut off early; pyogg throws an exception on open.)
Initially, I thought this was because OggOpusWriter always writes a sample rate of 0 (unspecified) in the Opus header. However, specifying the original sample rate in the header does not correct this duration issue:
import pyogg
sr = 12000
encoder = pyogg.OpusBufferedEncoder()
encoder.set_application("audio")
encoder.set_sampling_frequency(sr)
encoder.set_channels(1)
encoder.set_frame_size(20)
writer = pyogg.OggOpusWriter("should_be_1s.opus", encoder)
# HACK: Get OggOpusWriter to specify the sample rate in the header.
pyogg.OggOpusWriter._make_identification_header.__defaults__ = (sr,)
bytes_per_sample = 2
samples = bytearray(sr * bytes_per_sample)
writer.write(samples)
writer.close()
Running opusinfo on should_be_1s.opus correctly reports "Original sample rate: 12000Hz", but still reports a playback length of .25 seconds.
Any idea what's going wrong?
For supported sample rates other than 48k (i.e. 8k, 12k, 16k, 24k), OggOpusWriter generates an incorrectly reported duration, which causes bizarre behaviors depending on the audio player.
To reproduce:
examples/left-right-demo-5s.wavto 12k (e.g.sox left-right-demo-5s.wav -r 12k 12k.wav; mv 12k.wav left-right-demo-5s.wav)examples/03-write-ogg-opus.pyleft-right-demo-5s.wav.opuswith an incorrect duration (ffmpeg reports 1.26s; opusinfo reports 2.149s), which will confuse various tools and audio players (e.g. VLC and Totem cut off early; pyogg throws an exception on open.)Initially, I thought this was because OggOpusWriter always writes a sample rate of 0 (unspecified) in the Opus header. However, specifying the original sample rate in the header does not correct this duration issue:
Running
opusinfoonshould_be_1s.opuscorrectly reports "Original sample rate: 12000Hz", but still reports a playback length of .25 seconds. Any idea what's going wrong?