mediastreamvalidator bug: Error number -12847, format reader file not recognized
More and more recently I've been working with Apple's mediastreamvalidator, which (as the name implies) validates an MPEG-TS media stream from .m3u8 index files down to the codec and stream bitrate. While validating the streams produced by a project I am working on a few weeks ago, this ugly little bug popped up.
manoa:~ stu$ mediastreamvalidator validate http://media10.simplex.tv/content/2/270/11668/mpegts_256kb.m3u8
Validating http://media10.simplex.tv/content/2/270/11668/mpegts_256kb.m3u8 against iOS 4.0.1
ERROR: Invalid media segment: The validator helper exited due to a fatal error: failed to
create format reader: [errno: -12847] format reader file not recognized.
71: /content/2/270/11668/mpegts_256kb_33.ts
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ERROR: Invalid media segment: The validator helper exited due to a fatal error: failed to
create format reader: [errno: -12847] format reader file not recognized.
169: /content/2/270/11668/mpegts_256kb_82.ts
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WARNING: Media segment exceeds target duration by 30.240 % (6.98 vs. 10.00 seconds, limit is 20 %).
171: /content/2/270/11668/mpegts_256kb_83.ts
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WARNING: Media segment exceeds target duration by 100.533 % (6.02 vs. 3.00 seconds, limit is 20 %).
173: /content/2/270/11668/mpegts_256kb_84.ts
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Average segment duration: 9.75 seconds
Average segment bitrate: 350.01 kbit/s
Average segment structural overhead: 33.33 kbit/s (9.52 %)
Video codec: avc1
Video resolution: 640x360 pixels
Video frame rate: 25.00 fps
Average video bitrate: 253.45 kbit/s
H.264 profile: Baseline
H.264 level: 3.0
Audio codec: aac
Audio sample rate: 48000 Hz
Average audio bitrate: 63.23 kbit/s
The scary part in here is:
ERROR: Invalid media segment: The validator helper exited due to a fatal error: failed to
create format reader: [errno: -12847] format reader file not recognized.
Is the error due to a problem in my stream? Or is it the mediastreamvalidator tool itself? The tool even fails a self-test, which makes me suspect the tool over my stream as the cause. We need to know.
Despite misgivings about reporting bugs to the famously opaque Apple, I made the effort and created Apple Problem ID 8696703. To my utter shock, the contacted me because the