[FFmpeg-trac] #2686(avcodec:new): Native AAC encoder collapses at high bitrates on some samples

FFmpeg trac at avcodec.org
Wed Jun 19 06:07:22 CEST 2013


#2686: Native AAC encoder collapses at high bitrates on some samples
------------------------------------+-----------------------------------
             Reporter:  Kamedo2     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  aac         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+-----------------------------------

Comment (by Kamedo2):

 Yes, the output aac files sounded better with release 1.2.1 I've
 downloaded from
 http://www.ffmpeg.org/releases/ffmpeg-1.2.1.tar.bz2

 Still, the quality of the native aac at 320kbps is poorer than the native
 aac 256kbps.
 {{{
 ffmpeg version 1.2.1 Copyright (c) 2000-2013 the FFmpeg developers
   built on Jun 19 2013 12:38:13 with gcc 4.8.1 (GCC)
   configuration: --enable-gpl --enable-version3 --enable-libmp3lame
 --enable-lib
 vorbis --enable-nonfree --enable-libfdk-aac --enable-libvo_aacenc
 --enable-libfa
 ac --extra-ldflags=-static --extra-cflags='-march=nocona -mfpmath=sse'
 --optflag
 s=-O2
   libavutil      52. 18.100 / 52. 18.100
   libavcodec     54. 92.100 / 54. 92.100
   libavformat    54. 63.104 / 54. 63.104
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 42.103 /  3. 42.103
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
 [flac @ 01405c20] max_analyze_duration 5000000 reached at 5015510
 microseconds
 Input #0, flac, from 'ffmpeg_aac320k_collapse.flac
 ':
   Duration: 00:00:18.01, bitrate: 573 kb/s
     Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
 Output #0, mp4, to 'ffmpeg_aac320k_collapse.mp4':
   Metadata:
     encoder         : Lavf54.63.104
     Stream #0:0: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo,
 fltp, 32
 0 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (flac -> aac)
 Press [q] to stop, [?] for help
 size=     289kB time=00:00:18.01 bitrate= 131.3kbits/s
 video:0kB audio:285kB subtitle:0 global headers:0kB muxing overhead
 1.321136%
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:2>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker


More information about the FFmpeg-trac mailing list