Using ios device play mp4 with noisy sound

[Ken]

Summary of the bug:
I use ffmppeg to transcode video.mpg,and I play the newvideo.mp4 on pc(window 7) and andriod device is fine,but when play it on ios device(iphone 5 and the new ipad),the sound will noisy.
How to reproduce:

ffmpeg -i video.mpg -t 300 -vcodec libx264 -level 30 -r 25 -b:v 300k -profile:v baseline -s 640x480 -coder 0 -acodec libfaac -ac 2 -b:a 128k -ar 48000 newvideo.mp4
ffmpeg version 1.0 Copyright (c) 2000-2012 the FFmpeg developers
  built on Dec  3 2012 19:18:09 with gcc 4.1.2 (GCC) 20080704 (Red Hat 4.1.2-52)
  configuration: --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvpx --enable-libfaac --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-gpl --enable-postproc --enable-nonfree --enable-network --enable-protocol=tcp --enable-demuxer=rtsp --enable-decoder=h264
  libavutil      51. 73.101 / 51. 73.101
  libavcodec     54. 59.100 / 54. 59.100
  libavformat    54. 29.104 / 54. 29.104
  libavdevice    54.  2.101 / 54.  2.101
  libavfilter     3. 17.100 /  3. 17.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[mpeg @ 0xc6b3240] max_analyze_duration 5000000 reached at 5005000
Guessed Channel Layout for  Input Stream #0.1 : stereo
Input #0, mpeg, from video.mpg':
  Duration: 01:28:50.85, start: 0.280633, bitrate: 5277 kb/s
    Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x480 [SAR 8:9 DAR 4:3], 6500 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0:1[0xa0]: Audio: pcm_s16be, 48000 Hz, stereo, s16, 1536 kb/s
[libx264 @ 0xc6bb180] using SAR=1/1
[libx264 @ 0xc6bb180] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2
[libx264 @ 0xc6bb180] profile Constrained Baseline, level 3.0
[libx264 @ 0xc6bb180] 264 - core 129 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=300 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'newvideo.mp4':
  Metadata:
    encoder         : Lavf54.29.104
    Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 300 kb/s, 25 tbn, 25 tbc
    Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo, s16, 128 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg2video -> libx264)
  Stream #0:1 -> #0:1 (pcm_s16be -> libfaac)
Press [q] to stop, [?] for help
frame=   91 fps= 39 q=47.0 Lsize=     197kB time=00:00:03.64 bitrate= 443.5kbits/s dup=0 drop=15
video:141kB audio:52kB subtitle:0 global headers:0kB muxing overhead 2.174805%
[libx264 @ 0xc6bb180] frame I:1     Avg QP:22.00  size:   923
[libx264 @ 0xc6bb180] frame P:90    Avg QP:25.82  size:  1585
[libx264 @ 0xc6bb180] mb I  I16..4: 100.0%  0.0%  0.0%
[libx264 @ 0xc6bb180] mb P  I16..4:  6.0%  0.0%  0.3%  P16..4: 19.6%  2.7%  1.1%  0.0%  0.0%    skip:70.3%
[libx264 @ 0xc6bb180] final ratefactor: 25.61
[libx264 @ 0xc6bb180] coded y,uvDC,uvAC intra: 3.2% 27.1% 2.6% inter: 3.3% 12.3% 1.4%
[libx264 @ 0xc6bb180] i16 v,h,dc,p: 68% 18%  9%  5%
[libx264 @ 0xc6bb180] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 16% 58%  3%  2%  3%  3%  2%  2%
[libx264 @ 0xc6bb180] i8c dc,h,v,p: 76% 13% 11%  0%
[libx264 @ 0xc6bb180] ref P L0: 74.2% 13.8% 12.0%
[libx264 @ 0xc6bb180] kb/s:315.58
Received signal 2: terminating.

I try using different version ffmpeg to transcode video
1.ffmpeg 1.2
2.ffmpeg 1.06 & 1.0
3.ffmpeg 0.11.3
4.ffmpeg 0.10.7
P.S. the ffmpeg build confige is same.

1~3 version the sound is noisy,but when I use ffmpeg 0.10.7 the sound is fine.
So,is it the version bug??
And what is it mean:
the error message "Guessed Channel Layout for Input Stream #0.1 : stereo"

[Carl Eugen Hoyos]

Is the problem only reproducible with libfaac or also if you use the native aac encoder (-strict -2 -acodec aac)?
Please provide the input sample and please test current git head.

[Ken]

Sorry,the input smaple is copyright from muisc company,so I can not provide it.

I had a experiment with ffmpeg 1.0:

1. -vn and libfaac, it hear fine.
2. libx264 and mp3 ,it hear noisy.
3. libx264 and aac_coder 0, it hear noisy.
4. libx264 and -strict -2 -acodec aac, it hear noisy

I use ffmpeg 1.2,it from ffmpeg git, it hear noisy.

[Carl Eugen Hoyos]

If you want to reopen this ticket, please either:

• Provide a sample that allows to reproduce the problem

or

• use git bisect to find the version introducing the regression.