1014921 - Workaround 8x10 OMX H264 encoder/decoder mismatch on Flame

Status: RESOLVED FIXED

(Core :: WebRTC: Audio/Video, defect)

Description

[Randell Jesup [:jesup] (needinfo me)]

It appears that there's an encoder/decoder mismatch in the 8x10 DSP/firmware H.264 OMX codec; letting a call run with no IDRs rapidly builds up errors that creep around.  Careful examination shows they appear to show up quickly but with a circa 1-2 second IDR rate they never get obvious enough to see easily on a small screen. Most likely it's an error in the encoder in the estimate of what the decoder will decode the frame to, but that's just a guess.

This wallpapers the problem by forcing IDRs every 3 seconds if we don't send one for another reason.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

Attachment: Wallpaper 8x10 OMX H264 encode/decode mismatch by forcing IDRs

Comment 2

[Randell Jesup [:jesup] (needinfo me)]

Attachment: Wallpaper 8x10 OMX H264 encode/decode mismatch by forcing IDRs

Comment 3

[John Lin [:jhlin][:jolin]]

Comment on attachment 8427467 [details] [diff] [review]
Wallpaper 8x10 OMX H264 encode/decode mismatch by forcing IDRs

Review of attachment 8427467 [details] [diff] [review]:
-----------------------------------------------------------------

::: media/webrtc/signaling/src/media-conduit/WebrtcOMXH264VideoCodec.cpp
@@ +838,5 @@
> +
> +    // HACK for bug 1014921: 8x10 has encode/decode mismatches that build up errors
> +    // if you go too long without an IDR.  In normal use, bitrate will change often
> +    // enough to never hit this time limit.
> +    if ((time_since_last_idr > 3000) ||

nit: s/time_since_last_idr/timeSinceLastIDR/

Comment 4

[Andreas Gal :gal]

Has this been reported to the vendor?

Comment 5

[Diego Wilson [:diego]]

(In reply to Andreas Gal :gal from comment #4)
> Has this been reported to the vendor?

I am aware of this issue and will look further into it.

Comment 6

[Randell Jesup [:jesup] (needinfo me)]

Green try on the mass of patches -
https://tbpl.mozilla.org/?tree=Try&rev=36fed02b8193

Comment 7

[Randell Jesup [:jesup] (needinfo me)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/8013cb4ab729

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/8013cb4ab729