[FFmpeg-user] Realtime Audio Transcoding delay
shahab shirazi
shahab.sh.70 at gmail.com
Sun Dec 23 05:13:32 CET 2012
I used different parameters for -probesize and -analyzeduration but
unfortunately it didn't really help.
for testing purposes, I'm feeding avconv through pv at ~2000 bytes/s using
this command :
cat audiorecordtest.3gp | pv -L 2000 | avconv -i - -acodec g726 -ar 8k -b:a
8k -ac 1 -probesize 2k -analyzeduration 0 -f wav -
it takes about 15 seconds to get the first peice of data from stdout. Oddly
enough removing -b:a 8k reduces the delay to 5 seconds.
I have put the content of stderr at the end of this email. And here is the
file (audiorecordtest.3gp)
https://dl.dropbox.com/s/6of8jingvr76rhp/audiorecordtest.3gp?dl=1
I'd really appreciate it if you could test it and see if you can reduce the
delay to a reasonable amount.
Thank you so much,
Sean.
STDERR:
avconv version v9_beta2-501-g6d5b009, Copyright (c) 2000-2012 the Libav
developers
built on Dec 13 2012 08:55:05 with gcc 4.7 (Debian 4.7.2-4)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'pipe:':
Metadata:
major_brand : 3gp4
minor_version : 0
compatible_brands: isom3gp4
creation_time : 1946-12-23 03:14:57
Duration: 00:01:28.10, start: 0.000000, bitrate: N/A
Stream #0.0(eng): Audio: amrnb, 8000 Hz, mono, flt, 12 kb/s
Metadata:
creation_time : 1946-12-23 03:14:57
Output #0, wav, to 'pipe:':
Metadata:
major_brand : 3gp4
minor_version : 0
compatible_brands: isom3gp4
creation_time : 1946-12-23 03:14:57
ISFT : Lavf54.20.0
Stream #0.0(eng): Audio: g726, 8000 Hz, mono, s16, 16 kb/s
Metadata:
creation_time : 1946-12-23 03:14:57
Stream mapping:
Stream #0:0 -> #0:0 (amrnb -> g726)
Press ctrl-c to stop encoding
size= 1kB time=0.51 bitrate= 17.2kbits/s
size= 2kB time=1.02 bitrate= 16.6kbits/s
size= 3kB time=1.54 bitrate= 16.4kbits/s
size= 5kB time=2.56 bitrate= 16.2kbits/s
size= 6kB time=3.07 bitrate= 16.2kbits/s
size= 7kB time=3.58 bitrate= 16.2kbits/s
size= 9kB time=4.61 bitrate= 16.1kbits/s
size= 10kB time=5.12 bitrate= 16.1kbits/s
size= 11kB time=5.63 bitrate= 16.1kbits/s
size= 13kB time=6.66 bitrate= 16.1kbits/s
size= 14kB time=7.17 bitrate= 16.1kbits/s
size= 16kB time=8.19 bitrate= 16.1kbits/s
size= 17kB time=8.70 bitrate= 16.1kbits/s
size= 18kB time=9.22 bitrate= 16.1kbits/s
size= 19kB time=9.73 bitrate= 16.1kbits/s
size= 21kB time=10.75 bitrate= 16.1kbits/s
size= 22kB time=11.26 bitrate= 16.1kbits/s
size= 24kB time=12.29 bitrate= 16.1kbits/s
size= 25kB time=12.80 bitrate= 16.0kbits/s
size= 26kB time=13.31 bitrate= 16.0kbits/s
size= 28kB time=14.34 bitrate= 16.0kbits/s
size= 29kB time=14.85 bitrate= 16.0kbits/s
size= 30kB time=15.36 bitrate= 16.0kbits/s
size= 32kB time=16.38 bitrate= 16.0kbits/s
size= 33kB time=16.90 bitrate= 16.0kbits/s
size= 35kB time=17.92 bitrate= 16.0kbits/s
size= 36kB time=18.43 bitrate= 16.0kbits/s
size= 37kB time=18.94 bitrate= 16.0kbits/s
size= 39kB time=19.97 bitrate= 16.0kbits/s
size= 40kB time=20.48 bitrate= 16.0kbits/s
size= 41kB time=20.99 bitrate= 16.0kbits/s
size= 43kB time=22.02 bitrate= 16.0kbits/s
size= 44kB time=22.53 bitrate= 16.0kbits/s
size= 45kB time=23.04 bitrate= 16.0kbits/s
size= 47kB time=24.06 bitrate= 16.0kbits/s
size= 48kB time=24.58 bitrate= 16.0kbits/s
size= 49kB time=25.09 bitrate= 16.0kbits/s
size= 51kB time=26.11 bitrate= 16.0kbits/s
size= 52kB time=26.62 bitrate= 16.0kbits/s
size= 53kB time=27.14 bitrate= 16.0kbits/s
size= 55kB time=28.16 bitrate= 16.0kbits/s
size= 56kB time=28.67 bitrate= 16.0kbits/s
size= 58kB time=29.70 bitrate= 16.0kbits/s
size= 59kB time=30.21 bitrate= 16.0kbits/s
size= 60kB time=30.72 bitrate= 16.0kbits/s
size= 62kB time=31.74 bitrate= 16.0kbits/s
size= 63kB time=32.26 bitrate= 16.0kbits/s
size= 64kB time=32.77 bitrate= 16.0kbits/s
size= 66kB time=33.79 bitrate= 16.0kbits/s
size= 67kB time=34.30 bitrate= 16.0kbits/s
size= 68kB time=34.82 bitrate= 16.0kbits/s
size= 70kB time=35.84 bitrate= 16.0kbits/s
size= 71kB time=36.35 bitrate= 16.0kbits/s
size= 73kB time=37.38 bitrate= 16.0kbits/s
size= 74kB time=37.89 bitrate= 16.0kbits/s
size= 75kB time=38.40 bitrate= 16.0kbits/s
size= 77kB time=39.42 bitrate= 16.0kbits/s
size= 78kB time=39.94 bitrate= 16.0kbits/s
size= 79kB time=40.45 bitrate= 16.0kbits/s
size= 80kB time=40.96 bitrate= 16.0kbits/s
size= 82kB time=41.98 bitrate= 16.0kbits/s
size= 83kB time=42.50 bitrate= 16.0kbits/s
size= 85kB time=43.52 bitrate= 16.0kbits/s
size= 86kB time=44.03 bitrate= 16.0kbits/s
size= 87kB time=44.54 bitrate= 16.0kbits/s
size= 89kB time=45.57 bitrate= 16.0kbits/s
size= 90kB time=46.08 bitrate= 16.0kbits/s
size= 91kB time=46.59 bitrate= 16.0kbits/s
size= 93kB time=47.62 bitrate= 16.0kbits/s
size= 94kB time=48.13 bitrate= 16.0kbits/s
size= 96kB time=49.15 bitrate= 16.0kbits/s
size= 97kB time=49.66 bitrate= 16.0kbits/s
size= 98kB time=50.18 bitrate= 16.0kbits/s
size= 100kB time=51.20 bitrate= 16.0kbits/s
size= 101kB time=51.71 bitrate= 16.0kbits/s
size= 102kB time=52.22 bitrate= 16.0kbits/s
size= 104kB time=53.25 bitrate= 16.0kbits/s
size= 105kB time=53.76 bitrate= 16.0kbits/s
size= 106kB time=54.27 bitrate= 16.0kbits/s
size= 108kB time=55.30 bitrate= 16.0kbits/s
size= 109kB time=55.81 bitrate= 16.0kbits/s
size= 110kB time=56.32 bitrate= 16.0kbits/s
size= 112kB time=57.34 bitrate= 16.0kbits/s
size= 113kB time=57.86 bitrate= 16.0kbits/s
size= 114kB time=58.37 bitrate= 16.0kbits/s
size= 116kB time=59.39 bitrate= 16.0kbits/s
size= 117kB time=59.90 bitrate= 16.0kbits/s
size= 119kB time=60.93 bitrate= 16.0kbits/s
size= 120kB time=61.44 bitrate= 16.0kbits/s
size= 121kB time=61.95 bitrate= 16.0kbits/s
size= 123kB time=62.98 bitrate= 16.0kbits/s
size= 124kB time=63.49 bitrate= 16.0kbits/s
size= 125kB time=64.00 bitrate= 16.0kbits/s
size= 127kB time=65.02 bitrate= 16.0kbits/s
size= 128kB time=65.54 bitrate= 16.0kbits/s
size= 129kB time=66.05 bitrate= 16.0kbits/s
size= 131kB time=67.07 bitrate= 16.0kbits/s
size= 132kB time=67.58 bitrate= 16.0kbits/s
size= 133kB time=68.10 bitrate= 16.0kbits/s
size= 135kB time=69.12 bitrate= 16.0kbits/s
size= 136kB time=69.63 bitrate= 16.0kbits/s
size= 138kB time=70.66 bitrate= 16.0kbits/s
size= 139kB time=71.17 bitrate= 16.0kbits/s
size= 140kB time=71.68 bitrate= 16.0kbits/s
size= 142kB time=72.70 bitrate= 16.0kbits/s
size= 143kB time=73.22 bitrate= 16.0kbits/s
size= 144kB time=73.73 bitrate= 16.0kbits/s
size= 146kB time=74.75 bitrate= 16.0kbits/s
size= 147kB time=75.26 bitrate= 16.0kbits/s
size= 148kB time=75.78 bitrate= 16.0kbits/s
size= 150kB time=76.80 bitrate= 16.0kbits/s
size= 151kB time=77.31 bitrate= 16.0kbits/s
size= 152kB time=77.82 bitrate= 16.0kbits/s
size= 154kB time=78.85 bitrate= 16.0kbits/s
size= 155kB time=79.36 bitrate= 16.0kbits/s
size= 156kB time=79.87 bitrate= 16.0kbits/s
size= 158kB time=80.90 bitrate= 16.0kbits/s
size= 159kB time=81.41 bitrate= 16.0kbits/s
size= 161kB time=82.43 bitrate= 16.0kbits/s
size= 162kB time=82.94 bitrate= 16.0kbits/s
size= 163kB time=83.46 bitrate= 16.0kbits/s
size= 165kB time=84.48 bitrate= 16.0kbits/s
size= 166kB time=84.99 bitrate= 16.0kbits/s
size= 167kB time=85.50 bitrate= 16.0kbits/s
size= 169kB time=86.53 bitrate= 16.0kbits/s
size= 170kB time=87.04 bitrate= 16.0kbits/s
size= 171kB time=87.55 bitrate= 16.0kbits/s
size= 172kB time=88.10 bitrate= 16.0kbits/s
video:0kB audio:172kB global headers:0kB muxing overhead 0.044268%
On 22 Dec 2012 00:44, "Carl Eugen Hoyos" <cehoyos at ag.or.at> wrote:
> shahab shirazi <shahab.sh.70 <at> gmail.com> writes:
>
> > Here is the command I used for ffmpeg:
> > ffmpeg -i - -acodec g726 -ar 8k -ac 1 -b:a 8k -f wav -
>
> Complete, uncut console output missing.
> Try to set -probesize (and maybe -analyzeduration)
>
> Carl Eugen
>
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
More information about the ffmpeg-user
mailing list