[FFmpeg-devel] LATM BitStreamFilter

Michael Niedermayer michaelni
Fri May 1 03:35:25 CEST 2009

On Fri, May 01, 2009 at 01:31:31AM +0100, Robert Swain wrote:
> Michael Niedermayer wrote:
>> On Wed, Apr 29, 2009 at 08:21:06PM +1200, Paul Kendall wrote:
>>> Can I ask why LATM is preferred as a bit stream filter rather than
>>> as a decoder, or built into the AAC decoder, as ADTS is?
>> A simple use case
>> you have a demuxer that outputs AAC in LATM, and a muxer that doesnt
>> allow LATM.
>> Only a bitstream filter can fix this up in the current architecture unless
>> you want to change it to allow multiple demuxers to be chained, in which
>> case you could implement it as a demuxer too.
> This may be an idea.
> I think Paul was asking if the bitstream filters could only be inserted 
> after encoding/before multiplexing and not after demultiplexing/before 
> decoding which is where it is needed.

ffmpeg.c can be changed to insert them after demux too

>> you seem fixed on only the goal of decoding, this is not good, we need
>> to be able to remove as well as add LATM surrounding AAC.
> The vast vast majority of people outside of DVB stream broadcasting do not 
> need to add LATM. At least, I'm not aware of any other applications using 
> LATM at the moment.

so you have no plans to build a pirate dvb transmitter ;)

>> If the remuxng case with LATM removial as well as keeping LATM doesnt
>> work that would be reason to reject a patch.
> I think different parts should be considered separately. That is, I think 
> patches adding removal of LATM, addition of LATM or copying LATM should be 
> considered separately and the lack of any should not hold up inclusion of 
> any other as they're completely separate situations.

of course, but if someone submitted a patch that contained a bitstream
filter to remove it but it then worked only for decoding and not remuxing
that would be a reason to reject (thats really what ive meant)

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20090501/3168d205/attachment.pgp>

More information about the ffmpeg-devel mailing list