[Cherry-pick 2.0.1] Properly set #samples passed to encoder (#3204) #3239
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Summary: Some audio encoders expect specific, exact number of samples described as in `AVCodecContext.frame_size`. The `AVFrame.nb_samples` is set for the frames passed to `AVFilterGraph`, but frames coming out of the graph do not necessarily have the same numbr of frames. This causes issues with encoding OPUS (among others). This commit fixes it by inserting `asetnsamples` to filter graph if a fixed number of samples is requested. Note: It turned out that FFmpeg 4.1 has issue with OPUS encoding. It does not properly discard some sample. We should probably move the minimum required FFmpeg to 4.2, but I am not sure if we can enforce it via ABI. Work around will be to issue an warning if encoding OPUS with 4.1. (follow-up) Pull Request resolved: pytorch#3204 Reviewed By: nateanl Differential Revision: D44374668 Pulled By: mthrok fbshipit-source-id: 10ef5333dc0677dfb83c8e40b78edd8ded1b21dc
nateanl
approved these changes
Apr 5, 2023
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary:
Some audio encoders expect specific, exact number of samples described as in
AVCodecContext.frame_size.The
AVFrame.nb_samplesis set for the frames passed toAVFilterGraph, but frames coming out of the graph do not necessarily have the same numbr of frames.This causes issues with encoding OPUS (among others).
This commit fixes it by inserting
asetnsamplesto filter graph if a fixed number of samples is requested.Note:
It turned out that FFmpeg 4.1 has issue with OPUS encoding. It does not properly discard some sample. We should probably move the minimum required FFmpeg to 4.2, but I am not sure if we can enforce it via ABI. Work around will be to issue an warning if encoding OPUS with 4.1. (follow-up)
Pull Request resolved: #3204
Reviewed By: nateanl
Differential Revision: D44374668
Pulled By: mthrok
fbshipit-source-id: 10ef5333dc0677dfb83c8e40b78edd8ded1b21dc