Video quality

[thefastman]

Hi !
How can I setup quality ? Compared to VLC QtAV looks really not god.
I tried several render backends (widget, glwindget2 etc) and all of them sjow the same quality.

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[thefastman]

Ok, It's not a bug.
HLS stream contains more than one video track with different bitrate/resolution/quality

e:\tools\ffmpeg\bin>ffprobe.exe http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8
ffprobe version N-80906-gd5edb6c Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 5.4.0 (GCC)
  configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib
 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enab
le-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
able-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --e
nable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib

  libavutil      55. 28.100 / 55. 28.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 41.100 / 57. 41.100
  libavdevice    57.  0.102 / 57.  0.102
  libavfilter     6. 47.100 /  6. 47.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100
Input #0, hls,applehttp, from 'http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8':
  Duration: 00:30:01.00, start: 10.000000, bitrate: 0 kb/s
  Program 0
    Metadata:
      variant_bitrate : 200000
    Stream #0:0: Audio: aac (LC) ([15][0][0][0] / 0x000F), 22050 Hz, mono, fltp, 34 kb/s
    Metadata:
      variant_bitrate : 200000
    Stream #0:1: Video: h264 (Constrained Baseline) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/smpte170m/bt709), 192x144, 14.99 fps, 14.99 tbr, 90k tbn, 180k tbc
    Metadata:
      variant_bitrate : 200000
  Program 1
    Metadata:
      variant_bitrate : 311111
    Stream #0:2: Video: h264 (Constrained Baseline) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/smpte170m/bt709), 320x240, 29.97 fps, 29.97 tbr, 90k tbn, 180k tbc
    Metadata:
      variant_bitrate : 311111
    Stream #0:3: Audio: aac (LC) ([15][0][0][0] / 0x000F), 22050 Hz, mono, fltp, 34 kb/s
    Metadata:
      variant_bitrate : 311111
  Program 2
    Metadata:
      variant_bitrate : 484444
    Stream #0:4: Video: h264 (Constrained Baseline) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/smpte170m/bt709), 480x360, 29.97 fps, 29.97 tbr, 90k tbn, 180k tbc
    Metadata:
      variant_bitrate : 484444
    Stream #0:5: Audio: aac (LC) ([15][0][0][0] / 0x000F), 22050 Hz, mono, fltp, 34 kb/s
    Metadata:
      variant_bitrate : 484444
  Program 3
    Metadata:
      variant_bitrate : 737777
    Stream #0:6: Video: h264 (Constrained Baseline) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/smpte170m/bt709), 480x360, 29.97 fps, 29.97 tbr, 90k tbn, 180k tbc
    Metadata:
      variant_bitrate : 737777
    Stream #0:7: Audio: aac (LC) ([15][0][0][0] / 0x000F), 22050 Hz, mono, fltp, 34 kb/s
    Metadata:
      variant_bitrate : 737777

So, question now is: how I can choose/switch program/video track for playback ?
Thanks

[wang-bin]

what about ffplay?

[thefastman]

With ffplay is possible to set programm ID/stream number
For example:
ffplay -vst p:0 -i http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8

[alijafari97]

1. first send a get req to .m3u8 link
2. find out link of each quality
3. now you can set play("new link you received")

assume that hls link is http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/.m3u8
before using this link in player, send a get request to it.
in answer you will see something like this:
#EXTM3U
#EXT-X-VERSION:1
## Created with Unified Streaming Platform (version=1.10.28-22736)

# variants
#EXT-X-STREAM-INF:BANDWIDTH=493000,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=224x100,FRAME-RATE=24
tears-of-steel-audio_eng=64008-video_eng=401000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=932000,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=448x200,FRAME-RATE=24
tears-of-steel-audio_eng=128002-video_eng=751000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1197000,CODECS="mp4a.40.2,avc1.77.31",RESOLUTION=784x350,FRAME-RATE=24
tears-of-steel-audio_eng=128002-video_eng=1001000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1727000,CODECS="mp4a.40.2,avc1.100.40",RESOLUTION=1680x750,FRAME-RATE=24,VIDEO-RANGE=SDR
tears-of-steel-audio_eng=128002-video_eng=1501000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=2468000,CODECS="mp4a.40.2,avc1.100.40",RESOLUTION=1680x750,FRAME-RATE=24,VIDEO-RANGE=SDR
tears-of-steel-audio_eng=128002-video_eng=2200000.m3u8

# variants
#EXT-X-STREAM-INF:BANDWIDTH=68000,CODECS="mp4a.40.2"
tears-of-steel-audio_eng=64008.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=136000,CODECS="mp4a.40.2"
tears-of-steel-audio_eng=128002.m3u8

now you can select each quality you want. next line after "#EXT-X-STREAM-I ..." is its link that should replace with last part of main link.
for example, for 784p just use:
play("http://demo.unified-streaming.com/video/tears-of-steel/tears-of-steel.ism/tears-of-steel-audio_eng=128002-video_eng=1001000.m3u8")

if you add a setBufferValue(200) you can fix the freezing problem too.