diff options
Diffstat (limited to 'chromium/docs/website/site/audio-video/index.md')
| -rw-r--r-- | chromium/docs/website/site/audio-video/index.md | 159 |
1 files changed, 0 insertions, 159 deletions
diff --git a/chromium/docs/website/site/audio-video/index.md b/chromium/docs/website/site/audio-video/index.md deleted file mode 100644 index 4f2751b7296..00000000000 --- a/chromium/docs/website/site/audio-video/index.md +++ /dev/null @@ -1,159 +0,0 @@ ---- -breadcrumbs: [] -page_name: audio-video -title: Audio/Video ---- - -Everything you need to know about audio/video inside Chromium and Chromium OS! - -### Whom To Contact - -It's best to have discussions on chromium-dev@chromium.org or -media-dev@chromium.org for media specific matters. - -We are component -[Internals>Media](https://bugs.chromium.org/p/chromium/issues/list?can=2&q=component%3AInternals%3EMedia) -on the Chromium bug tracker. - -### Documentation - -See -[media/README.md](https://chromium.googlesource.com/chromium/src/+/HEAD/media/README.md). -For historical reference, here's the original [design doc for HTML5 -audio/video](/developers/design-documents/video). - -### Codec and Container Support - -Container formats - -* MP4 (QuickTime/ MOV / MPEG4) -* Ogg -* WebM -* WAV - -* HLS \[Only on Android and only single-origin manifests\] - -Codec formats (Decode Only) - -==Audio== - -* FLAC -* MP3 -* Opus -* PCM 8-bit unsigned integer -* PCM 16-bit signed integer little endian -* PCM 32-bit float little endian -* PCM μ-law -* Vorbis - -* AAC \[Main, LC, HE profiles only, xHE-AAC on Android P+\] \[Google - Chrome only\] - -* AMR-NB \[Google Chrome OS only\] -* AMR-WB \[Google Chrome OS only\] -* GSM \[Google Chrome OS Only\] - -==Video== - -* VP8 -* VP9 - -* AV1 \[Only Chrome OS, Linux, macOS, and Windows at present\] - -* Theora \[Except on Android variants\] - -* H.264 \[Google Chrome only\] -* H.265 \[Google Chrome OS on Intel Gen 11-based Chromebooks for - protected content playback only\] - -* MPEG-4 \[Google Chrome OS only\] - -### Code Location - -**Chromium** - -media/ - Home to all things media! -media/audio - OS audio input/output abstractions -media/video/capture - OS camera input abstraction -media/video - software/hardware video decoder interfaces + implementations -third_party/ffmpeg - Chromium's copy of FFmpeg -third_party/libvpx - Chromium's copy of libvpx - -**Blink** - -third_party/blink/renderer/core/html/media/html_media_element.{cpp,h,idl} - -media element base class - -third_party/blink/renderer/core/html/media/html_audio_element.{cpp,h,idl} - -audio element implementation - -third_party/blink/renderer/core/html/media/html_video_element.{cpp,h,idl} - -video element implementation - -**Particularly Interesting Bits** - -media/base/mime_util.cc - defines canPlayType() behaviour and file extension -mapping - -media/blink/buffered_data_source.{cc,h} - Chromium's main implementation of -DataSource for the media pipeline - -media/blink/buffered_resource_loader.{cc,h} - Implements the sliding window -buffering strategy (see below) - -third_party/blink/public/platform/web_media_player.h - Blink's media player -interface for providing HTML5 audio/video functionality - -media/blink/webmediaplayer_impl.{cc,h} - Chromium's main implementation of -WebMediaPlayer - -### How does everything get instantiated? - -WebFrameClient::createMediaPlayer() is the Blink embedder API for creating a -WebMediaPlayer and passing it back to Blink. Every HTML5 audio/video element -will ask the embedder to create a WebMediaPlayer. - -For Chromium this is handled in RenderFrameImpl. - -### GN Flags - -There are a few GN flags which can alter the behaviour of Chromium's HTML5 -audio/video implementation. - -ffmpeg_branding - -Overrides which version of FFmpeg to use - -Default: $(branding) - -Values: - -Chrome - includes additional proprietary codecs (MP3, etc..) for use with Google -Chrome - -Chromium - builds default set of codecs - -proprietary_codecs - -Alters the list of codecs Chromium claims to support, which affects -<source> and canPlayType() behaviour - -Default: 0(gyp)/false(gn) - -Values: - -0/false - <source> and canPlayType() assume the default set of codecs - -1/true - <source> and canPlayType() assume they support additional -proprietary codecs - -### How the %#$& does buffering work? - -Chromium uses a combination of range requests and an in-memory sliding window to -buffer media. We have a low and high watermark that is used to determine when to -purposely stall the HTTP request and when to resume the HTTP request. - -It's complicated, so here's a picture: - -[<img alt="image" -src="/audio-video/ChromiumMediaBuffering.png">](/audio-video/ChromiumMediaBuffering.png)
\ No newline at end of file |