-
Notifications
You must be signed in to change notification settings - Fork 515
fix(avc): Handle streams that don't start with NAL start codes #1857
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Merged
cfsmp3
merged 1 commit into
CCExtractor:master
from
cfsmp3:fix/issue-1626-broken-avc-stream
Dec 20, 2025
Merged
fix(avc): Handle streams that don't start with NAL start codes #1857
cfsmp3
merged 1 commit into
CCExtractor:master
from
cfsmp3:fix/issue-1626-broken-avc-stream
Dec 20, 2025
Conversation
This file contains hidden or 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
…ractor#1626) The AVC parser would fail with "Leading bytes are non-zero" error when processing HLS/Twitch stream segments that start mid-stream without proper NAL unit headers at the beginning. Root cause: When process_avc encountered non-zero leading bytes, it returned an error with 0 bytes processed. The C code would not remove any bytes from the buffer, causing subsequent data to accumulate with the corrupt beginning, leading to infinite errors. Fix: - Add find_nal_start_code() to search for valid NAL start codes - If buffer doesn't start with 0x00 0x00, search for first NAL start - Skip garbage data before first valid NAL unit - Return full buffer length when no NAL found (clears the buffer) - Change forbidden_zero_bit error from fatal to skip-and-continue Tested with 6 Twitch HLS sample files - all now process correctly. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <[email protected]>
Collaborator
CCExtractor CI platform finished running the test files on linux. Below is a summary of the test results, when compared to test for commit a0593c6...:
NOTE: The following tests have been failing on the master branch as well as the PR:
Congratulations: Merging this PR would fix the following tests:
All tests passing on the master branch were passed completely. Check the result page for more info. |
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
Problem
The AVC parser would fail with "Leading bytes are non-zero" error when processing HLS/Twitch stream segments. These segments often start mid-stream without proper NAL unit headers at the beginning.
Root cause: When
process_avcencountered non-zero leading bytes, it returned an error with 0 bytes processed. The C code would not remove any bytes from the buffer, causing subsequent data to accumulate with the corrupt beginning, leading to infinite errors and no caption extraction.Solution
find_nal_start_code()function to search for valid NAL start codes (3-byte or 4-byte)0x00 0x00, search for first NAL start codeTest plan
find_nal_start_code)Before fix:
After fix:
Extracted captions:
🤖 Generated with Claude Code