- From: Aymeric Vitte <vitteaymeric@gmail.com>
- Date: Wed, 26 Mar 2014 18:38:31 +0100
- To: Aaron Colwell <acolwell@chromium.org>
- CC: Jay Munro <jaymunro@microsoft.com>, "public-html-media@w3.org" <public-html-media@w3.org>, Michael Smith <mike@w3.org>
- Message-ID: <53331097.6010109@gmail.com>
Thanks for your answers. Submitting the chunks of a fragmented mp4 file (created with MP4Box for example) does not work in Chrome, as far as I understand this is not normal. If you are including MP3, can't you include non fragmented MP4 and WebM? How can I achieve what I want to do? This would be incredible that this is not feasible. Regards Aymeric Le 26/03/2014 17:32, Aaron Colwell a écrit : > Hi Aymeric, > > Comments inline... > > On Wed, Mar 26, 2014 at 8:24 AM, Aymeric Vitte <vitteaymeric@gmail.com > <mailto:vitteaymeric@gmail.com>> wrote: > > Thanks, yes we can share experiences (I thought it was not > implemented in FF, from which version?), I saw your tutorial > already, very well explained, what I want to do is a bit different > and very simple: > > Usually you use something like <video src='movie.mp4' />, then you > get the chunks via HTTP and the video is displayed. > > I want to do exactly the same thing, I receive the chunks (from > the Peersm protocol via WebSockets or WebRTC Data Channels) and > MSE displays the movie. > > > MSE was not designed for this. To support this in the generic case the > code fetching the data needs to understand the file format so it can > properly fetch the necessary chunks for playback and make tradeoffs > about the size of the chunk to fetch vs the amount of bytes actually > needed in that chunk. > > > I have read from some Aaron posts that MSE only works with > fragmented files, in addition you have to submit the fragments as > defined in the manifest file (or at least the initialization > segment? I have not tested this for now). > > > The manifest file isn't required by MSE, but that is typically how > specs like DASH describe the layout & location of the fragments. > > > It does not work for mp3 (as far as I saw the Web Audio API does > not allow to do what I want to do too). > > > I plan on submitting an MSE byte stream format specification for MP3 > and AAC in ADTS in the next day or two. I'm just putting the final > touches on the language. Chrome has experimental support for both of > these formats right now. > > > Format available inside the browsers are not numerous, now the API > is rectricting to fragmented files, so I find it extremely limited. > > > I'm sorry you feel this way. Fragmented files allow segments of media > to be self contained and only contain local references. This makes > dealing with chunked media much easier. For the generic case you have > to deal with absolute file references and arbitrary file layout which > is much more difficult to work with. The API would look very different > and would not be able to provide many of the features that MSE does. > > > I have some hard time believing that no API did envision that you > might want to stream video and audio based on the received chunks, > is it the case? > > > Again, your use case is different from what MSE goals were. It appears > that you simply want to replace the UAs HTTP fetching code with your > own P2P code. That is fine, but not what MSE was designed to solve. > > > Do IE and FF only implement it too for fragmented files? > > > Yes. They conform to the MSE spec > <https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html> > and implement the requirements laid out in the byte stream format > specifications > <https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/byte-stream-format-registry.html> they > have chosen to support. For MP4 in particular, this means fragmented > files only. > > I hope this helps you understand, > > Aaron > > > Regards > > Aymeric > > Le 25/03/2014 17:46, Jay Munro a écrit : > > How are you preparing your source files? Do they have the > initialization box/packet (normally on any mp4 or webm file) > for at least the first segment? > > I've created a MSE player for DASH mp4 files.. I'm not an > expert, but I've gotten it to work on a single stream on IE > and Firefox. I would like to get it to work on chrome, so > maybe we can share experiences. > > I don't know if this will help, but here's a blog post I wrote > on one way to do it (there seems to be quite a few) > http://blogs.msdn.com/b/mediastuff/archive/2014/02/19/video-streaming-without-plug-ins-or-special-servers.aspx > > -Jay > > > -----Original Message----- > From: Aymeric Vitte [mailto:vitteaymeric@gmail.com > <mailto:vitteaymeric@gmail.com>] > Sent: Tuesday, March 25, 2014 4:23 AM > To: public-html-media@w3.org <mailto:public-html-media@w3.org> > Cc: acolwell@chromium.org <mailto:acolwell@chromium.org> > Subject: Streaming with Media Source > > Hi, > > For [1] I have started to implement Streaming for audio and > video using the Media Source API, the app is retrieving chunks > and is appending them to the "source" of audio/video tags. > > This was supposed to be simple but it is not, the API (or at > least the Chrome implementation) seems to handle only adaptive > rate/manifest structures both for mp4 and webm, it's unclear > if the audio tag is supported. > > I am not an expert in video/audio format but I don't see very > well what's the issue to append chunks to a destination, or to > turn it into a stream (since I am participating to the Streams > API, I know it's not there yet) outside of other interfaces > such as WebRTC. > > For the final phase of the project, WebRTC will be used but > with DataChannels, so the issue remains. > > I have looked in all existing APIs and unless I am missing > something, I still don't see how to achieve this simple thing, > how can it be done? > > Regards, > > Aymeric > > [1] http://www.peersm.com > > -- > Peersm : http://www.peersm.com > node-Tor : https://www.github.com/Ayms/node-Tor > GitHub : https://www.github.com/Ayms > > > > -- > Peersm : http://www.peersm.com > node-Tor : https://www.github.com/Ayms/node-Tor > GitHub : https://www.github.com/Ayms > > -- Peersm : http://www.peersm.com node-Tor : https://www.github.com/Ayms/node-Tor GitHub : https://www.github.com/Ayms
Received on Wednesday, 26 March 2014 17:39:07 UTC