Re: [libav-devel] [PATCH] applehttp: Expose the stream bitrate via metadata
On Wed, 20 Apr 2011, Ronald S. Bultje wrote: Hi, On Wed, Apr 20, 2011 at 7:49 AM, Martin Storsjö mar...@martin.st wrote: This helps callers to intelligently switch between bitrate variants. --- libavformat/applehttp.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) Doesn't AVCodecContext have a bit_rate integer for this purpose? It does, but this is for a slightly different use. The bitrate in AVCodecContext is for the actual bitrate of that stream only, while this would convey the total bitrate of the whole bitrate variant that this stream belongs to. So for that, a different name perhaps would be better, like variant_total_bitrate or something similar? // Martin___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
Re: [libav-devel] [PATCH] applehttp: Expose the stream bitrate via metadata
On Wed, 20 Apr 2011, Martin Storsjö wrote: On Wed, 20 Apr 2011, Ronald S. Bultje wrote: Hi, On Wed, Apr 20, 2011 at 8:05 AM, Martin Storsjö mar...@martin.st wrote: On Wed, 20 Apr 2011, Ronald S. Bultje wrote: On Wed, Apr 20, 2011 at 7:49 AM, Martin Storsjö mar...@martin.st wrote: This helps callers to intelligently switch between bitrate variants. --- libavformat/applehttp.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) Doesn't AVCodecContext have a bit_rate integer for this purpose? It does, but this is for a slightly different use. The bitrate in AVCodecContext is for the actual bitrate of that stream only, while this would convey the total bitrate of the whole bitrate variant that this stream belongs to. So for that, a different name perhaps would be better, like variant_total_bitrate or something similar? What's the difference? As Vladimir explained on irc - it's the total bitrate of all streams within the same bitrate variants. If I've got a stream with two variants, 100 kbps and 500 kbps, both having audio and video, I'd set 100 kbps as variant_total_bitrate on the two streams from the first variant and 500 kbps on the other two. The audio stream bitrate may well be the same, e.g. 32 kbps in both of them, while the video would be 68 in the former and 468 in the latter. Therefore, when switching, the caller needs to know which streams belong to the same bitrate variant, so that he doesn't accidentally pull from more than one variant at a time, and preferrably also know what their total bitrate is. To add more to the explanation - currently, the info about which AVStream belongs to which variant stream actually is available, it's stored in AVStream-id, where the int value says which variant it is a part of - all AVStreams with identical id belong together. But someone from XBMC asked me yesterday to provide the variant's total bitrate, too, which is useful for making better decisions on switching variants. // Martin___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
Re: [libav-devel] [PATCH] applehttp: Expose the stream bitrate via metadata
Hi, On Wed, Apr 20, 2011 at 9:44 AM, Martin Storsjö mar...@martin.st wrote: To add more to the explanation - currently, the info about which AVStream belongs to which variant stream actually is available, it's stored in AVStream-id, where the int value says which variant it is a part of - all AVStreams with identical id belong together. But someone from XBMC asked me yesterday to provide the variant's total bitrate, too, which is useful for making better decisions on switching variants. At this point, do we know the bitrates of the individual streams? We could simply put that in AVStream-codec-bit_rate and let callers add it up... Ronald ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
Re: [libav-devel] [PATCH] applehttp: Expose the stream bitrate via metadata
On Wed, 20 Apr 2011, Ronald S. Bultje wrote: On Wed, Apr 20, 2011 at 9:44 AM, Martin Storsjö mar...@martin.st wrote: To add more to the explanation - currently, the info about which AVStream belongs to which variant stream actually is available, it's stored in AVStream-id, where the int value says which variant it is a part of - all AVStreams with identical id belong together. But someone from XBMC asked me yesterday to provide the variant's total bitrate, too, which is useful for making better decisions on switching variants. At this point, do we know the bitrates of the individual streams? We could simply put that in AVStream-codec-bit_rate and let callers add it up... Only if the chained mpegts demuxer sets it, and it appears it doesn't. Also, within the applehttp metadata, there is an explicit bitrate field saying what the nominal bitrate of that variant is, we should pass it through somewhere at least. So, would a variant_bitrate metadata key be acceptable? Anton? // Martin___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
