On 22/05/2011, at 12.57, Martin Storsjö wrote: > On Sun, 22 May 2011, Gil Pedersen wrote: > >> On 22/05/2011, at 12.17, "Martin Storsjö" <[email protected]> wrote: >> >>> On Sun, 22 May 2011, Gil Pedersen wrote: >>> >>>> The RTP hinting done by libav is quite limited, as it is, and you're >>>> already likely to use mp4box, or similar tool, for any non-basic >>>> hinting. >>> >>> Oh, what limitations have you run into, that mp4box handles better? >> >> It has a whole host of rtp hinting related options, as can be seen on the >> man page: >> http://manpages.ubuntu.com/manpages/natty/man1/mp4box.1.html >> >> I think the only option libav supports is LATM payload streaming, but I >> might be wrong. > > Well, comparing a list of options perhaps isn't indicative of the number > of features. We do support RTP hinting for all the formats that our RTP > muxer supports, which is quite a few. There's just not many public options > to control its behaviour, yet at least. > > I don't really see any critical feature among those options that we are > missing. The MTU isn't configurable in our case (adding an AVOption for > that is quite easy if someone has a need for it), and we don't support > copying hint tracks (I think), adding extra custom SDP data nor choosing > whether to prefer dynamic payload IDs over static ones. The number of > packets to concatenate into an RTP packet is configurable via max_delay > though.
I'm just stating how it looks at the moment, and I agree that several of the mp4box options could be implemented quite easily in libav. Other options, like interleaving and fast start, will require more substantial changes to the movenc muxer since they can't be realized using the current implementation. Ie. you need to create a temporary file and write everything to disk twice for it to be viable. I don't know if this is in the pipeline for libav. For my purposes I don't need RTP hinting anymore, but a fast start option would be very welcome. > If someone has a concrete usecase where some other parameter needs to be > adjusted, where the default isn't ok, we can of course try to make that > configurable, as we're discussing with the LATM case right now. Sure, this sounds nice, but most people who look at the tools will see that many already recommend a combination of ffmpeg and mp4box and likely decide to use that. It's a very limited audience that will know you are listening and have time to wait for the features to be implemented. Anyway, I wasn't trying to start a discussion on the RTP hinting features of libav, just trying to point out that there are alternatives for special use-cases you might miss. /Gil _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
