On Thursday, May 12, 2011 18:59:33 Charlie X. Liu wrote: > Which HDMI receiver chip? Indeed, that's my question as well :-) Anyway, this question comes up regularly. V4L2 provides timestamps for each frame, so that's no problem. But my understanding is that ALSA does not give you timestamps, so if there are processing delays between audio and video, then you have no way of knowing. The obvious solution is to talk to the ALSA people to see if some sort of timestamping is possible, but nobody has done that. This is either because everyone that needs it hacks around it instead of trying to really solve it, or because it is never a problem in practice. Hope this helps! Regards, Hans > > -----Original Message----- > From: linux-media-owner@xxxxxxxxxxxxxxx > [mailto:linux-media-owner@xxxxxxxxxxxxxxx] On Behalf Of Bhupesh SHARMA > Sent: Wednesday, May 11, 2011 10:49 PM > To: linux-media@xxxxxxxxxxxxxxx > Cc: Laurent Pinchart; Guennadi Liakhovetski; Hans Verkuil > Subject: Audio Video synchronization for data received from a HDMI receiver > chip > > Hi Linux media folks, > > We are considering putting an advanced HDMI receiver chip on our SoC, > to allow reception of HDMI audio and video. The chip receives HDMI data > from a host like a set-up box or DVD player. It provides a video data > interface > and SPDIF/I2S audio data interface. > > We plan to support the HDMI video using the V4L2 framework and the HDMI > audio using ALSA framework. > > Now, what seems to be intriguing us is how the audio-video synchronization > will be maintained? Will a separate bridging entity required to ensure the > same > or whether this can be left upon a user space application like mplayer or > gstreamer. > > Also is there a existing interface between the V4L2 and ALSA frameworks and > the same > can be used in our design? > > Regards, > Bhupesh > ST Microelectronics > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
