871288 - libstagefright MPEG2TS assertion failure with CHECK_EQ(br.getBits(4),1u) and crash [@android::MPEG2PSExtractor::dequeuePES]

Status: RESOLVED WORKSFORME

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

Description

[Christoph Diehl [:posidron]]

Attachment: testcase

STR

* In the folder of the testcase run: python3.3 -m http.server
* Open the Firefox app in the B2G emulator
* Attach GDB to the highest plugin-container process id
* Open the .mp4 file inside the Firefox app


The following CHECK fails:

"frameworks/base/media/libstagefright/mpeg2ts/MPEG2PSExtractor.cpp:419 CHECK_EQ( br.getBits(4),1u) failed: 15 vs. 1"


Tested inside the B2G emulator.
Build fingerprint: 'Android/full/generic:4.0.4.0.4.0.4/OPENMASTER/eng.cdiehl.20130423.062518:eng/test-keys'

Comment 1

[cajbir (:cajbir)]

Looks like a bug in libstagefright. Adding Sotaro who's the expert in that area.

Comment 2

[Sotaro Ikeda [:sotaro]]

File name's extension is mp4. But the file content seems Mpeg2 ps, not mp4.

Comment 3

[Sotaro Ikeda [:sotaro]]

Christoph, how do you get the video?

Comment 4

[Christoph Diehl [:posidron]]

I renamed the file to .mp4 because the original extension did not play automatically in the Firefox app.

Comment 5

[Sotaro Ikeda [:sotaro]]

What is the intent of the test? Mpeg2 is not supproted format in Firefox OS.

Comment 6

[Sotaro Ikeda [:sotaro]]

(In reply to Christoph Diehl [:cdiehl] from comment #4)
> I renamed the file to .mp4

From where do you get the file?

Comment 7

[Christoph Diehl [:posidron]]

Found the file on some random site returned by Google. If it is not supported why are we parsing it? :-)

Comment 8

[Sotaro Ikeda [:sotaro]]

Firefox OS does not modify android's stagefright so far. The stagefright do not watch files' extension when doing a playback. It sniffs the media file. Android's device normally control supporting media formats by modifying DataSource::RegisterDefaultSniffers().

http://androidxref.com/4.0.4/xref/frameworks/base/media/libstagefright/DataSource.cpp#105

Comment 9

[Sotaro Ikeda [:sotaro]]

And recently, Firefox add only aac and amr file format support only for local app in Bug 847006. So, supported media formats are different between web content and local app.

Comment 10

[cajbir (:cajbir)]

(In reply to Sotaro Ikeda [:sotaro] from comment #9)
> And recently, Firefox add only aac and amr file format support only for
> local app in Bug 847006. So, supported media formats are different between
> web content and local app.

Can we tell stagefright to return an error rather than assert when sniffing content?

Comment 11

[Sotaro Ikeda [:sotaro]]

> Can we tell stagefright to return an error rather than assert when sniffing
> content?

What is the the assert? stagefright do not call assert during sniffing. Stagefright call assert when parsing for playback.

Comment 12

[Sotaro Ikeda [:sotaro]]

Call stagefright's sniffing can be moved into OmxDecoder in gecko and can create android::MediaExtractor by specifying mime type.

Comment 13

[Sotaro Ikeda [:sotaro]]

comment #12 is like move MediaExtractor::Create()'s implementation to OmxDecoder.

http://androidxref.com/4.0.4/xref/frameworks/base/media/libstagefright/MediaExtractor.cpp#53