[chromium-discuss] MediaInternals: MP4 Decoding - Add additional media logging in ConvertFrame path

[Jamie Stackhouse]

Currently we are trying to debug an issue with content and understand why
Chrome is failing to produce a valid frame for demuxing. I've opened
chrome://media-internals, and the pipeline stalls at the message: "Failed
to prepare video sample for decode".

https://cs.chromium.org/chromium/src/media/formats/mp4/mp4_stream_parser.cc?type=cs&q=%22Failed+to+prepare+video+sample+for+decode%22&sq=package:chromium&g=0&l=815

Using cs.chromium.org I was able to find where that was output and find the
AVC implementation for ConvertFrame. From there, however, I'm about to open
up Chrome with verbose logging enabled to see if the output logs from DVLOG
provide any more insight as to why a sample wasn't able to be prepared.

It would be great from the perspective of debugging these issues if the
reason why ConvertFrame ends up returning false was included in the media
log as well.

{
"time": 15572.023000000045,
"key": "for_suspended_start",
"value": false
},
{
"time": 15572.023000000045,
"key": "pipeline_buffering_state",
"value": "BUFFERING_HAVE_ENOUGH"
},
{
"time": 25851.789999999106,
"key": "error",
"value": "Failed to prepare video sample for decode"
},
{
"time": 25851.883999999613,
"key": "error",
"value": "Append: stream parsing failed. Data size=131072
append_window_start=0 append_window_end=inf"
},
{
"time": 25856.890999998897,
"key": "pipeline_error",
"value": "CHUNK_DEMUXER_ERROR_APPEND_FAILED"
},