[Icecast] Webm files written without duration in header

[Marvin Scholz]

On 2 May 2019, at 0:50, Sytze Visser wrote:

> Hi Marvin
>
> I followed this advice for updating moov flags in mp4 and it "streams"
> directly from the file location on the server with html5 video:
> https://rigor.com/blog/optimizing-mp4-video-for-fast-streaming.
>
> Progressive downloading, seeking and video time all works 100% on a 195MB
> file.
>

Yes thats an entirely different thing than live-streaming though.
Icecast is made for live-streaming not for serving on-demand video,
any webserver can do that just fine, no need for Icecast in that
case :)

> Regards
>
> On Wed, May 1, 2019 at 10:19 PM Marvin Scholz <epirat07 at gmail.com> wrote:
>
>>
>>
>> On 1 May 2019, at 22:06, Sytze Visser wrote:
>>
>>> Hi Fred.
>>>
>>> Appreciate your response.
>>>
>>> Maybe in my explanation I have some red and green apples, but I can
>>> agree that my understanding is as you explained it. 😊
>>>
>>> The point is that if I can successfully stream mp4 with H.264 and AAC
>>> encoding without any issues to icecast, I can then use ffmpeg to
>>
>> Hi,
>> just a quick thing to clarify before you waste too much time on this:
>>
>> MP4 is not streamable due to the way the format works. The header/trailer
>> that a valid mp4 files needs to have, requires "knowledge" of the whole
>> file which makes it impossible to stream it.
>>
>> What HLS or DASH does is not "streaming" in the "traditional" sense of
>> streaming but rather it is downloading small complete file chunks that
>> nowadays mostly use fragmented MP4.
>>
>> You can't stream MP4 with Icecast.
>> If you for some reason have to stream H.264 you could use MPEG TS.
>> Note that this might have licensing implications as MPEG TS is not
>> royalty-free.
>>
>>> turn it into HLS which then solves my iOS support issue. The CPU
>>> cost of repackaging MP4 into HLS architecture should be minimal
>>> because at the core it’s all H.264. No transcoding! Low CPU objective
>>> achieved!
>>> Additional bonus is that I already use Apach2 with icecast and
>>> integrating the whole lot into my existing infrastructure is easy.
>>>
>>> My question remains
>>> If webm/ogv is supported but mp4 not, what are the technical differences
>>> in how icecast handles the one and not the other? What does icecast
>>> manage/do for supported formats as opposed to unsupported ones?
>>>
>>> Kind regards
>>>
>>> On Wed, 2019-05-01 at 19:56 +0200, Sytze Visser wrote:
>>>> I read somewhere that MP4 is not supported on icecast, which is a
>>>> pity. I have invested a lot in an icecast based audio solution and
>>>> want expand it with video.
>>>
>>> It all depends on what one means by 'MP4' (which is more a marketing
>>> term than a technical one). AAC+ (aka 'high efficiency' AAC) works very
>>> well on IceCast, albeit that only covers the audio side on the
>>> equation.
>>>
>>>> So my question is now:
>>>> MP4 (H.264) is a close relative of HLS (can also be H.264) which
>>>> brings me very close to a solution.
>>>
>>> You're mixing apples and oranges here (pun accidental). H.264 is a
>>> content encoding, like MPEG Layer III (so-called 'MP3') or OggVorbis.
>>> HLS OTOH is a streaming architecture, and as such is largely orthogonal
>>> to the content encoding used. It works by segmenting the media stream
>>> into discrete files and then distributing them via HTTP(S). The big
>>> advantage of this approach is that standard 'garden variety' web
>>> servers (think Apache) can be used to serve the streams, which makes it
>>> play particularly well with CDNs, at the cost of significantly greater
>>> complexity in the encoder and player components. No specialized
>>> 'streaming server' (such as Icecast) is required in the HLS ecosystem
>>> at all.
>>>
>>> Cheers!
>>>
>>>
>>> |---------------------------------------------------------------------|
>>> | Frederick F. Gleason, Jr. |             Chief Developer             |
>>> |                           |             Paravel Systems             |
>>> |---------------------------------------------------------------------|
>>> |  An expert is a person who avoids the small errors while he sweeps  |
>>> |  on to the grand fallacy.                                           |
>>> |                                                                     |
>>> |                                              -- Benjamin Stolberg   |
>>> |---------------------------------------------------------------------|
>>>
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