As per the Issue 640820 owner, assigning this issue to @liberato.
@liberato -- Could you please look into this issue, kindly reassign if it has nothing to do with your changes.
Thanks.

ClusterFuzz has detected this issue as fixed in range 515364:515426.

Detailed report: https://clusterfuzz.com/testcase?key=6180982209380352

Fuzzer: libFuzzer_mediasource_MP4_FLAC_pipeline_integration_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Integer-overflow
Crash Address: 
Crash State:
  flac_lpc_16_c
  decode_subframe_lpc
  decode_subframe
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=513674:513694
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=515364:515426

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6180982209380352

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reference.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 6180982209380352 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.