Predator and CL did not provide any possible suspects.
Using Code Search for the file, "amrwbdec.c" adding the concern owner in Cc.
Suspecting Commit#
https://chromium.googlesource.com/chromium/third_party/ffmpeg.git/+/6bd79ba59f46a8b3133f28faae53b75540469803

Pardon me if it is wrongly assigned
Thank You.

I dont seem to have access to the "Detailed report: https://clusterfuzz.com/testcase?key=4999992424267776", can you provide ubsan output for this issue ?

Emailed you (michaelni@gmx.at) the details along w/ minimized test case.

Thank you!

Looking at the details, this looks like the issue fixed in the commit already identified by  Comment 1 by msrchandra@chromium.org, Mar 22 
that is 6bd79ba59f46a8b3133f28faae53b75540469803

The details point to a shift at ../../third_party/ffmpeg/libavcodec/amrwbdec.c:265:69: runtime error: left shift of negative value -1

Theres a shift prior to 6bd79ba59f46a8b3133f28faae53b75540469803 at this position but not afterwards

Marking the issue as Fixed as per comment# 5, so changing the status to Fixed.
Please correct me if I am wrong.
Thank You

ClusterFuzz has detected this issue as fixed in range 477380:477461.

Detailed report: https://clusterfuzz.com/testcase?key=4999992424267776

Fuzzer: libFuzzer_media_pipeline_integration_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Undefined-shift
Crash Address: 
Crash State:
  decode_pitch_lag_high
  decode_pitch_vector
  amrwb_decode_frame
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=423338:423416
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=477380:477461

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4999992424267776


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

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