Stream switching/adapting in HLS

takoi · 2012-04-25 12:29

Here's an example:
http://links.latincdn.com/vod/hls/big_bu...p_001.m3u8

It contains the following streams:

Code:

#EXTM3U

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1896000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001/big_buck_bunny_1080p_h264_HLS_16x9_480p_001.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1596000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_1500Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_1500Kb.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1296000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_1200Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_1200Kb.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=996000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_900Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_900Kb.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=864000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_768Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_768Kb.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=608000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_512Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_512Kb.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=352000

big_buck_bunny_1080p_h264_HLS_16x9_480p_001_256Kb/big_buck_bunny_1080p_h264_HLS_16x9_480p_001_256Kb.m3u8

Code:

Stream #0:0: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 1896000

    Stream #0:1: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 852x480 [SAR 1:1 DAR 71:40], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 1896000

    Stream #0:2: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 1596000

    Stream #0:3: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 852x480 [SAR 1:1 DAR 71:40], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 1596000

    Stream #0:4: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 1296000

    Stream #0:5: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 852x480 [SAR 1:1 DAR 71:40], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 1296000

    Stream #0:6: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 996000

    Stream #0:7: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 996000

    Stream #0:8: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 864000

    Stream #0:9: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 864000

    Stream #0:10: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 608000

    Stream #0:11: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 512x288 [SAR 1:1 DAR 16:9], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 608000

    Stream #0:12: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, s16

    Metadata:

      variant_bitrate : 352000

    Stream #0:13: Video: h264 (Baseline) ([27][0][0][0] / 0x001B), yuv420p, 512x288 [SAR 1:1 DAR 16:9], 24 tbr, 90k tbn, 48 tbc

    Metadata:

      variant_bitrate : 352000

How, if you play the master m3u8, xbmc seems to always just pick the first stream and stick with it, no matter what. Not automatically switching as expected. Am i doing something wrong here or is it that adaptive bitrate is not supported?
If it isn't, is there a way to pick the stream to play manually? For audio I can use setAudioStream through python or select it through gui, which works fine. But what about video stream?

**spiff** · 2012-04-30 14:09

not yet supported. i started working on it ages ago, there's a (dysfunctional) pr. haven't found the time to look at it again.

however the fact that nrk is moving to hls, will bump it on my priorities..