[pluzz.francetv.fr] sound shredded

[jobwat]

On a direct extract with youtube-dl, and whatever the format (-f) chosen, the sound "jumps" (as in: sound for 1s, blank 1s, sound, blank...)

I found a small video to play with (27M), here is the download output (from a ubuntu server in France):

# youtube-dl --verbose -f m3u8-306 -o bad_sound_vid.mp4 http://pluzz.francetv.fr/videos/super_4_,115453339.html
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['--verbose', '-f', 'm3u8-306', '-o', 'bad_sound_vid.mp4', 'http://pluzz.francetv.fr/videos/super_4_,115453339.html']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2014.12.16.2
[debug] Python version 2.7.8 - Linux-3.17.0-119-armv7l-with-Ubuntu-14.10-utopic
[debug] exe versions: avconv 11-6, avprobe 11-6
[debug] Proxy map: {}
[pluzz.francetv.fr] super_4_,115453339: Downloading webpage
[pluzz.francetv.fr] 115453339: Downloading video JSON
[pluzz.francetv.fr] 115453339: Downloading geo restriction info
[pluzz.francetv.fr] 115453339: Downloading m3u8 information
[debug] Invoking downloader on u'http://ftvodhdsecz-f.akamaihd.net/i/streaming-adaptatif_france-dom-tom/2015/S01/J6/115453339-20150103-,398,632,934,k.mp4.csmil/index_0_av.m3u8?null='
[download] Destination: bad_sound_vid.mp4
avconv version 11-6:11-1, Copyright (c) 2000-2014 the Libav developers
  built on Sep 26 2014 14:44:07 with gcc 4.9.1 (Ubuntu/Linaro 4.9.1-15ubuntu1)
[mpegts @ 0x68600] Estimating duration from bitrate, this may be inaccurate
Input #0, hls,applehttp, from 'http://ftvodhdsecz-f.akamaihd.net/i/streaming-adaptatif_france-dom-tom/2015/S01/J6/115453339-20150103-,398,632,934,k.mp4.csmil/index_0_av.m3u8?null=':
  Duration: 00:11:55.83, start: 0.100667, bitrate: N/A
  Program 0 
    Metadata:
      variant_bitrate : 0
    Stream #0.0: Video: h264 (Constrained Baseline), yuv420p, 320x180 [PAR 1:1 DAR 16:9], 25 fps, 90k tbn, 50 tbc
    Stream #0.1: Audio: aac, 48000 Hz, stereo, fltp, 76 kb/s
Output #0, mp4, to 'bad_sound_vid.mp4.part':
  Metadata:
    encoder         : Lavf56.1.0
    Stream #0.0: Video: libx264, yuv420p, 320x180 [PAR 1:1 DAR 16:9], q=2-31, 90k tbn, 90k tbc
    Stream #0.1: Audio: aac, 48000 Hz, stereo, 76 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press ctrl-c to stop encoding
frame=17895 fps=1727 q=-1.0 Lsize=   27265kB time=715.76 bitrate= 312.1kbits/s    
video:21268kB audio:5593kB other streams:0kB global headers:1kB muxing overhead: 1.506251%
[avconv] 27919679 bytes

I found that extracting the sound forcing mp3 format and then re-mixing it with video just works.. (from a Mac)

ffmpeg -i bad_sound_vid.mp4 -vn -acodec mp3 just_sound.mp3
ffmpeg -i bad_sound_vid.mp4 -c:v copy -an just_vid.m4v
ffmpeg -i just_vid.m4v -i just_sound.mp3 all_good.mp4 

I'm wondering if an encoding setting could be passed to avconv from the guts of youtube-dl, or as a command line option. I tried few things with no success

# youtube-dl --version
2014.12.16.2
# avconv --version
avconv version 11-6:11-1, Copyright (c) 2000-2014 the Libav developers
  built on Sep 26 2014 14:44:07 with gcc 4.9.1 (Ubuntu/Linaro 4.9.1-15ubuntu1)
# cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.10
DISTRIB_CODENAME=utopic
DISTRIB_DESCRIPTION="Ubuntu 14.10"

[jaimeMF]

I can reproduce it with libav and VLC (but mpv and mplayer play it fine). If I use ffmpeg it plays without problem.