1023625 - MOZ_FFMPEG should only be defined on Linux

Status: RESOLVED WONTFIX

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

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

I'm told MOZ_FFMPEG is defined when building Fennec.

http://mxr.mozilla.org/mozilla-central/source/configure.in#5240

5233 dnl ========================================================
5234 dnl FFmpeg H264/AAC Decoding Support
5235 dnl ========================================================
5236 case "$OS_TARGET" in
5237 WINNT|Darwin|Android)
5238     ;;
5239 *)
5240     MOZ_FFMPEG=1
5241     ;;
5242 esac

Why are we defining MOZ_FFMPEG on non Linux platforms? Shouldn't we only be defining MOZ_FFMPEG=1 on Linux only?

Comment 1

[Jan Beich]

There's more to Unix desktop than just Linux. Per bug 987773 the above should allow to dlopen libavformat on Solaris, DragonFly, FreeBSD, OpenBSD, NetBSD. Other platforms such as Darwin/X11 or OS/2 suffer from more serious issues.

Comment 2

[Jan Beich]

Attachment: disable on B2G Desktop Linux

Is this what you want?

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

Comment on attachment 8454892 [details] [diff] [review]
disable on B2G Desktop Linux

Review of attachment 8454892 [details] [diff] [review]:
-----------------------------------------------------------------

::: configure.in
@@ +5205,5 @@
>  case "$OS_TARGET" in
>  WINNT|Darwin|Android)
>      ;;
>  *)
> +    if test -z "$MOZ_B2G"; then

I was thinking something more like "if we're building for desktop linux, MOZ_FFMPEG=1.

Comment 4

[Jan Beich]

Are you talking about code clarity or functional issue ?

Comment 5

[Chris Pearce [:cpearce (Not reading bugmail)]]

Functional use. We should only use ffmpeg on desktop linux and B2G desktop on Linux (I had forgotten about B2G desktop until now).

Comment 6

[Jan Beich]

TBPL supports very limited list of OS_TARGET and those platforms are already excluded. Linux along with every non-TPBL platform is left to fallthrough to MOZ_FFMPEG=1. For example, Fennec and B2G/Gonk only exist on OS_TARGET=Android thus excluded.

MOZ_PULSEAUDIO and MOZ_GSTREAMER use the same kind of case block and also have AC_MSG_ERROR but don't break TBPL. So, we may end up talking in circles unless you provide the log.

Is this about policy then? Are only TBPL or officially supported platforms should use MOZ_FFMPEG=1?

Comment 7

[Chris Pearce [:cpearce (Not reading bugmail)]]

(In reply to Jan Beich from comment #6)
> Is this about policy then? Are only TBPL or officially supported platforms
> should use MOZ_FFMPEG=1?

Yes this is about policy. We should only build ffmpeg media support on platforms that we use ffmpeg (desktop Linux and B2G Desktop on Linux). It's confusing for developers working on other platforms if ffmpeg is being built but not used on that platform.

Comment 8

[Jan Beich]

(In reply to Chris Pearce (:cpearce) from comment #7)
> It's confusing for developers working on other platforms if ffmpeg is being built
> but not used on that platform.

This is still lacking in context. What are those "other" platforms? Are they on TBPL (Tier1) or not (Tier3)?

https://developer.mozilla.org/en/docs/Supported_build_configurations

According to bug 941298 MOZ_FFMPEG is needed for MSE/H264. The code is still preffed off and not even hooked for canPlayType. However, disabling the feature for non-technical reason would hinder, say, trying to make FreeBSD support on par with Linux.

Or have I missed the place where MOZ_FFMPEG is used to also enable in bug 987773 ? Even for GMP/EME it may still be possible for Tier3 to support depending on how out-of-process communication works (see nspluginwrapper).

Comment 9

[Chris Pearce [:cpearce (Not reading bugmail)]]

(In reply to Jan Beich from comment #8)
> (In reply to Chris Pearce (:cpearce) from comment #7)
> > It's confusing for developers working on other platforms if ffmpeg is being built
> > but not used on that platform.
> 
> This is still lacking in context. What are those "other" platforms? Are they
> on TBPL (Tier1) or not (Tier3)?

Android, FirefoxOS.


> https://developer.mozilla.org/en/docs/Supported_build_configurations
> 
> According to bug 941298 MOZ_FFMPEG is needed for MSE/H264. The code is still
> preffed off and not even hooked for canPlayType. However, disabling the
> feature for non-technical reason would hinder, say, trying to make FreeBSD
> support on par with Linux.

I didn't realise FreeBSD needed this. I don't want to deny FreeBSD MSE support.

It seems we should be only enabling FFMPEG on desktop Unix that is not MacOSX. That should catch FreeBSD.