Sample aspect ratio not implemented in AVC?

[Pulstar]

Hello.. I have a large pile of MPEGs that I want to batch-encode into AVC but it seems that the x264 codecs (and H.264 decoders) I used either don't implement SAR or ignore it completely. I'm positive that my MPEGs are 4:3 so resizing every file individually would take much more time for 'odd' resolutions like 352x240.. Is there a workaround or should I just stick with MPEG4 ASP?

[J_Darnley]

Are you telling x264 (or other program) the aspect ratio? Are you aware of the --sar option for x264?

[Pulstar]

I used both x264vfw and the library in AVIDemux, and I set the SAR fields to 4 and 3 respectively.. but when I play back the AVI/MP4s (tried both containers) using either latest builds of ffdshow or CoreAVC I get the stretched video that doesn't comform to the specified 4:3 ratio. Whereas XviDs display 4:3 correctly when decoded using libavcodec.

[Dark Shikari]

I used x264vfwAnd there's your problem.

If you set the container aspect correctly, the aspect ratio on your files will be fine in any sane player. Video for Windows generally means AVI, and AVI has no widely supported method of setting aspect ratio.

Your entire post seems to be backwards--it's ASP that, in practice, doesn't support sample aspect ratio (many players don't support the flags), while AVC always does.

[LoRd_MuldeR]

I used both x264vfw and the library in AVIDemux, and I set the SAR fields to 4 and 3 respectively..

Note that in Avidemux you must specify the PAR (Pixel Aspect Ratio).

For example for a 4:3 PAL video (720x576) you'd need to specify a PAR of 16:15 to get it stretched to 4:3 at playback time.

Also there is the "as input" checkbox ;)

Last but not least you must make sure that both, the decoder and the renderer, apply the PAR correctly.

In order to make sure that none of the filters in your DirectShow chain are at fault, try to play the video in MPlayer or VLC.

[Pulstar]

Is the x264 library in AVIDemux the same as x264vfw? I've just encoded an MPEG using AVIDemux, using the x264 and AAC profiles in an MP4 container (ignoring the File Not Saved Correctly error message) and the resultant video is in stretched widescreen format..

Oddly enough XviD AVIs with a SAR of 4:3 play just fine in MPC using libavcodec.

[LoRd_MuldeR]

Is the x264 library in AVIDemux the same as x264vfw?

Nope. Avidemux doesn't use VfW. It's a cross-platform application and there's no VfW outside the Windows world ;)

Avidemux comes with "built-in" x264 encoder...

I've just encoded an MPEG using AVIDemux, using the x264 and AAC profiles in an MP4 container (ignoring the File Not Saved Correctly error message) and the resultant video is in stretched widescreen format..

Obviously your encode was not completed successfully :rolleyes:

[Pulstar]

Note that in Avidemux you must specify the PAR (Pixel Aspect Ratio).

For example for a 4:3 PAL video (720x576) you'd need to specify a PAR of 16:15 to get it stretched to 4:3 at playback time.

Also there is the "as input" checkbox ;)

Last but not least you must make sure that both, the decoder and the renderer, apply the PAR correctly.

In order to make sure that none of the filters in your DirectShow chain are at fault, try to play the video in MPlayer or VLC.

Where to set PAR in AVIDemux? Also I'm using the latest build yet I get errors when exporting to MP4. Is there a log file I can read to see if it's an error on my part?

Edit - It seems setting 'same as input' solved my problem! But the issue of MP4 errors remains.

Thank you and to everyone who replied :)

[LoRd_MuldeR]

Where to set PAR in AVIDemux? Also I'm using the latest build yet I get errors when exporting to MP4. Is there a log file I can read to see if it's an error on my part?

Choose "MPEG-4 AVC (x264)" from the list and click the "Configure" button. On the "Misc" tab there are the "Pixel Aspect Ratio" options.

The log is found at:
C:\Documents and Settings\LoRd_MuldeR\avidemux\admlog.txt

[Pulstar]

[x264] AQ mode: 20[x264] AQ
[x264] Opening x264 for 352 x 240
[x264] rc.f_qcompress = 0.60
[x264] rc.i_vbv_max_bitrate = 0
[x264] rc.i_vbv_buffer_size = 0
[x264] rc.f_vbv_buffer_init = 0.90
[x264] analyse.b_fast_pskip = 0
[x264] analyse.b_dct_decimate = 1
[x264] b_interlaced = 0
[x264] analyse.i_direct_mv_pred = 1
[x264] rc.i_qp_min = 10
[x264] rc.i_qp_max = 51
[x264] rc.i_qp_step = 4
[x264] i_frame_reference = 1
[x264] i_scenecut_threshold = 40
[x264] i_keyint_min = 25
[x264] i_keyint_max = 250
[x264] i_bframe = 2
[x264] i_bframe_bias = 0
[x264] b_bframe_pyramid = 0
[x264] i_bframe_adaptive = 1
[x264] analyse.b_weighted_bipred = 1
[x264] b_cabac = 1
[x264] analyse.i_trellis = 0
[x264] analyse.i_subpel_refine = 6
[x264] analyse.b_chroma_me = 1
[x264] b_deblocking_filter = 1
[x264] i_deblocking_filter_alphac0 = 0
[x264] i_deblocking_filter_beta = 0
[x264] analyse.i_me_method = 1
[x264] analyse.i_me_range = 16
[x264] analyse.b_transform_8x8 = 1
[x264] analyse.b_mixed_references = 0
[x264] analyse.i_noise_reduction = 0
[x264] rc.i_aq_mode = 1
[x264] rc.f_aq_strength = 1.00
[x264] _8x8P is on
[x264] _8x8B is on
[x264] _8x8I is on
[x264] _4x4I is on
[x264] VBV_max_br = 0
[x264] vbv_buffer_size = 0
[x264] f_vbv_buffer_init = 0.900000
x264 [info]: using SAR=200/219
x264 [info]: using cpu capabilities: MMX2
x264 [info]: profile High, level 1.3
[x264] init ok (atom mode: 1)
[x264] using threads
[x264] Nb nal: 3

[x264] Encoder ready, w: 352 h: 240 mode: 1[x264] has 45 extra bytes
We have extradata for video in copy mode (45)
[Bridge] Going to time 0
[Bridge] Starting with time 0, shift 0
[Bridge] Ending with time 0, sample 0
[Bridge] Going to time 0
[Bridge] Going to time 0
[FAAC] Incoming Fq :44100
[FAAC] : Sample input:2048, max byte output1536
[Faac] Initialized :
[Faac]Version : 1.26.1 (Oct 30 2007) UNSTABLE
[Faac]Bitrate : 64000
[Faac]Mpeg2 (1)/4(0) : 0
[Faac]Use lfe ) : 0
[Faac]Sample output : 1024
[Faac]Bitrate : 128000
PacketQueue MP4 audioQ created
[AudioQueueThread] Starting
skipping frame: 0 size: 0
skipping frame: 1 size: 0
[LavFormat] Bitrate 128
[lavc] Output #0, mp4, to 'C:\Test\Test.mp4':

[lavc] Stream #0.0
[lavc] : Video: 0x0000, 352x240, q=2-31, 2000 kb/s
[lavc] , 29.97 fps(c)
[lavc]

[lavc] Stream #0.1
[lavc] : Audio: 0x0000, 44100 Hz, stereo, 128 kb/s
[lavc]

lavformat mpeg muxer initialized
LavMuxer:Audio DTS is too low 0 / 0!
LavMuxer:Audio DTS is too low 0 / 0!
LavMuxer:Audio DTS is too low 23219 / 0!
DMX_audio Going out of bound (position : 6515000 asked 5000 end6519955)
DMX_audio Going out of bound (position : 6519955 asked 5000 end6519955)
**PKTZ:READ ERROR
**END OF AUDIO STREAM
EditorPacket:Read failed; retrying (were at seg 0sample 10263168
/ 10264984)
EditorPacket : End of *last* stream
read failed, end of stream ?
EditorPacket:Read failed; retrying (were at seg 0sample 10263168
/ 10264984)
EditorPacket : End of *last* stream
read failed, end of stream ?
[Bridge] End of stream
EditorPacket:Read failed; retrying (were at seg 0sample 10263168
/ 10264984)
EditorPacket : End of *last* stream
read failed, end of stream ?
[Bridge] End of stream
EditorPacket:Read failed; retrying (were at seg 0sample 10263168
/ 10264984)
EditorPacket : End of *last* stream
read failed, end of stream ?
[Bridge] End of stream
EditorPacket:Read failed; retrying (were at seg 0sample 10263168
/ 10264984)
EditorPacket : End of *last* stream
read failed, end of stream ?
[Bridge] End of stream
[bridge] No data in 0 max 37444 out 0
[AudioQueueThread] Exiting
[AudioThread] Target 4294901760, got 10261504, 0.002389 %
LavMuxer:Audio DTS is too low 232663945 / 0!
2nd pass, sent 6977 frames
x264 [info]: slice I:49 Avg QP:18.27 size: 9176 PSNR Mean Y:46.47 U:49.02 V:50.72 Avg:47.31 Global:46.97
x264 [info]: slice P:2725 Avg QP:20.14 size: 2285 PSNR Mean Y:43.94 U:46.64 V:48.75 Avg:44.83 Global:44.39
x264 [info]: slice B:4202 Avg QP:21.05 size: 530 PSNR Mean Y:43.91 U:46.84 V:48.83 Avg:44.83 Global:44.35
x264 [info]: consecutive B-frames: 3.2% 23.2% 73.6%
x264 [info]: mb I I16..4: 4.8% 73.6% 21.5%
x264 [info]: mb P I16..4: 1.2% 6.0% 1.4% P16..4: 44.2% 20.1% 14.0% 0.0% 0.0% skip:13.2%
x264 [info]: mb B I16..4: 0.9% 0.0% 0.0% B16..8: 20.1% 1.7% 1.4% direct:14.8% skip:61.2% L0:29.1% L1:51.5% BI:19.3%
x264 [info]: 8x8 transform intra:62.4% inter:49.9%
x264 [info]: SSIM Mean Y:0.9874746
x264 [info]: PSNR Mean Y:43.944 U:46.778 V:48.811 Avg:44.850 Global:44.380 kb/s:306.03
[Bridge] Destroying bridge
[FAAC] Deleting faac
[lavc] Destroyed
Deleting post proc
[GTK] Changing size to 352 240
Cleaning up
Waiting for Spidermonkey to finish...
Cleaning up Spidermonkey.
[SDL] Quitting...
End of cleanup

Images stat:
___________
Max memory consumed (MB) : 1732
Current memory consumed (MB) : 0
Max image used : 15
Cur image used : 0
Global mem stat
______________
Memory consumed: 0 (MB)

Is the out of bound error normal? The MPEG stream is correct afaik, otherwise VirtualDub would have failed to encode it to AVI knowing how sensitive it is to broken frames.

[LoRd_MuldeR]

Is the out of bound error normal? The MPEG stream is correct afaik, otherwise VirtualDub would have failed to encode it to AVI knowing how sensitive it is to broken frames.

Sure you are using the latest build ??? :confused:

Can't see such message here. The log is from MEPG-2 to x264/AAC in MP4 container:

***************************
Avidemux v2.4.3 (r4507)
***************************
http://www.avidemux.org
Code : Mean, JSC, Gruntster
GFX : Nestor Di , nestordi@augcyl.org
Design : Jakub Misak
FreeBSD : Anish Mistry, amistry@am-productions.biz
Audio : Mihail Zenkov
MacOsX : Kuisathaverat
Win32 : Gruntster

Compiler: GCC 4.2.1-sjlj (mingw32-2)
Build Target: Microsoft Windows (x86)
User Interface: Qt (4.4.3)
Operating System: Microsoft Windows Server 2003 Standard Edition Service Pack 2 (5.2.3790; 64-bit)

Initialising prefs
Preferences found and loaded
[cpuCaps]Checking CPU capabilities
MMX detected
MMXEXT detected
SSE detected
SSE2 detected
SSE3 detected
SSSE3 detected
[cpuCaps]End of CPU capabilities check (cpuMask :ffffffff)

Registering Encoders
*********************
MJPEG encoder registered
Xvid-4 encoder registered
FFmpeg encoder registered

3 encoder(s) registered

[SDL] Version: 1.2.13
[SDL] Setting video driver to Microsoft DirectX
[SDL] Initialisation succeeded
[SDL] Video Driver: directx

Initializing WinSock
WinSock ok
Initializing Dithering tables
[xvid] Initializing global Xvid 4
[xvid] Build: xvid-1.2.1
[xvid] SIMD supported: (1cf)
MMX
MMXEXT
SSE
SSE2
Initializing postproc
Deleting post proc
updating post proc
Disabled

Registering Filters
*********************

Using real audio device
[Win32] Creating audio device
Unable to load [libamrnb-2.dll]: The specified module could not be found.

Unable to load [libdts.dll]: The specified module could not be found.

Spidermonkey initialized.

[Locale] Locale: en_US
[Locale] Loading language file D:/Avidemux 2.4/i18n/qt_en_US FAILED
[Locale] Loading language file D:/Avidemux 2.4/i18n/avidemux_en_US FAILED
[Locale] Test: &Edit -> &Edit

Directory C:\Documents and Settings\LoRd_MuldeR\Application Data\avidemux\custom exists.Good.
ignored:x264 (Psy RDO).off
ignored:x264.new
ignored:x264.old
ignored:x264_presets.zip
Found 6 custom script(s), adding them
Custom menu built
The screen seems to be 1680 x 1021 px
Found 20 video encoder(s)
Found 10 audio encoder(s)
Found 13 format(s)
No crash file (C:\Documents and Settings\LoRd_MuldeR\Application Data\avidemux/crash.js)
ba010000 -> ba010000

Mpeg file detected...
594d4441 -> 594d4441

New mpeg index file detected..

opening d2v file : D:\_Temp\VIDEO_TS\Chilipeppers_Milano_1.mpg.idx
For file :D:\_Temp\VIDEO_TS\Chilipeppers_Milano_1.mpg
Pic :720x576, 25000 fps
#Gop :1299
#Img :15580
Creating mpeg PS demuxer main Pid: E0
There was several files, but dont append was forced

Simple loading:
file: D:\_Temp\VIDEO_TS\Chilipeppers_Milano_1.mpg, size: 986658752
found 1 files
Done
Dropping 0 last B/P frames
Creating start sequence (38)..

0000 : ...³-.@#.L#‚.... 00 00 01 b3 2d 02 40 23 1d 4c 23 82 10 10 10 10
0010 : ................ 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
0020 : ........ ..... 10 10 10 10 10 10 10 10 20 20 20 10 10 10 10 10
0030 : .. 10 10
Image :129448, seqLen : 86 seq 0 0 1 b3
Reordering mpeg frames
Frame dropped
Frame dropped
Renumbered Gop 1 /1299

opening dmx file for audio track : D:\_Temp\VIDEO_TS\Chilipeppers_Milano_1.mpg.idx
Creating mpeg PS demuxer main Pid: C0
There was several files, but dont append was forced

Simple loading:
file: D:\_Temp\VIDEO_TS\Chilipeppers_Milano_1.mpg, size: 986658752
found 1 files
Done
Building index with 1299 sync points
Filling audio header
Audio index loaded, probing...
Probing track:0, pid: 0 pes:c0

DMX audio initialized (24923808 bytes)
With 1299 sync point
Mpeg index file successfully read
The video codec has some extradata (86 bytes)

0000 : ...³-.@#.L#‚.... 00 00 01 b3 2d 02 40 23 1d 4c 23 82 10 10 10 10
0010 : ................ 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
0020 : ........ ..... 10 10 10 10 10 10 10 10 20 20 20 10 10 10 10 10
0030 : .. 10 10 20 20 20 20 20 20 20 20 20 20 20 20 20 20
0040 : 00 000@@P...µ 20 20 30 30 20 20 30 30 30 40 40 50 00 00 01 b5
0050 : .‚.... 14 82 00 01 00 00
Deleting post proc
Initializing postproc
Deleting post proc
updating post proc
Disabled
[Editor] Duration in seconds: 623, in samples: 27479592

Decoder FCC: MPEG (4745504D)
Searching decoder (720 x 576, extradataSize:86)...

using Mpeg1/2 codec (libmpeg2)
[lavc] Build: 3352580
[lavc] Enabling MT decoder with 4 threads
[lavc] Decoder init: CODEC_ID_MPEG2VIDEO video decoder initialized!

checking for B-Frames...
scanning 125 frames
* # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * # * #
* # * # * # * # * # * # * # * # * #

Mmm this appear to have b-frame...

And the index is ok

Frames re-ordered, B-frame friendly now :)
End of B-frame check

Editor :Audio streamer initialized
Audio codec: MP2-3
Mpeg1/2 audio codec created
[RDR] Resizing to 720 x 576
[lavc] No accelerated colorspace conversion found


** conf updated **
[Custom] Invoked
[Custom] 2/6 scripts
Spidermonkey compiling "C:\Documents and Settings\LoRd_MuldeR\Application Data\avidemux\custom/x264 (CRF HQ).js"...Done.
Spidermonkey executing "C:\Documents and Settings\LoRd_MuldeR\Application Data\avidemux\custom/x264 (CRF HQ).js"...Deleting post proc
updating post proc
Disabled
Codec ...
[codec]X264
[conf ]AQ=22

Codec X264 found
codec conf is AQ
Valid descriptor found for audio codec
Done.

configuring codec :18
Changed
**saving:**
Output format:7
AVI family
[x264] using C:\test.mp4.stat as logfile

[x264] AQ mode: 22[x264] AQ
[x264] Opening x264 for 720 x 576
[x264] rc.f_qcompress = 0.60
[x264] rc.i_vbv_max_bitrate = 0
[x264] rc.i_vbv_buffer_size = 0
[x264] rc.f_vbv_buffer_init = 0.90
[x264] analyse.b_fast_pskip = 0
[x264] analyse.b_dct_decimate = 1
[x264] b_interlaced = 0
[x264] analyse.i_direct_mv_pred = 3
[x264] rc.i_qp_min = 10
[x264] rc.i_qp_max = 51
[x264] rc.i_qp_step = 4
[x264] i_frame_reference = 10
[x264] i_scenecut_threshold = 40
[x264] i_keyint_min = 25
[x264] i_keyint_max = 250
[x264] i_bframe = 8
[x264] i_bframe_bias = 0
[x264] b_bframe_pyramid = 1
[x264] i_bframe_adaptive = 2
[x264] analyse.b_weighted_bipred = 1
[x264] b_cabac = 1
[x264] analyse.i_trellis = 2
[x264] analyse.i_subpel_refine = 9
[x264] analyse.b_chroma_me = 1
[x264] b_deblocking_filter = 1
[x264] i_deblocking_filter_alphac0 = 0
[x264] i_deblocking_filter_beta = 0
[x264] analyse.i_me_method = 3
[x264] analyse.i_me_range = 24
[x264] analyse.b_transform_8x8 = 1
[x264] analyse.b_mixed_references = 1
[x264] analyse.i_noise_reduction = 0
[x264] rc.i_aq_mode = 1
[x264] rc.f_aq_strength = 1.00
[x264] _8x8P is on
[x264] _8x8B is on
[x264] _4x4 is on
[x264] _8x8I is on
[x264] _4x4I is on
[x264] VBV_max_br = 0
[x264] vbv_buffer_size = 0
[x264] f_vbv_buffer_init = 0.900000
x264 [info]: using SAR=16/15
x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 Cache64
x264 [info]: profile High, level 3.1
[x264] init ok (atom mode: 1)
[x264] using threads
[x264] Nb nal: 3

[x264] Encoder ready, w: 720 h: 576 mode: 1[x264] has 47 extra bytes
We have extradata for video in copy mode (47)
[Bridge] Going to time 61440
[Bridge] Starting with time 61440, shift 0
[Bridge] Ending with time 61440, sample 0
[Bridge] Going to time 61440
[Bridge] Going to time 61440
[FAAC] Incoming Fq :44100
[FAAC] : Sample input:2048, max byte output1536
[Faac] Initialized :
[Faac]Version : 1.26.1 (Oct 30 2007) UNSTABLE
[Faac]Bitrate : 64000
[Faac]Mpeg2 (1)/4(0) : 0
[Faac]Use lfe ) : 0
[Faac]Sample output : 1024
[Faac]Bitrate : 128000
PacketQueue MP4 audioQ created
[AudioQueueThread] Starting
skipping frame: 0 size: 0
skipping frame: 1 size: 0
skipping frame: 2 size: 0
skipping frame: 3 size: 0
skipping frame: 4 size: 0
skipping frame: 5 size: 0
skipping frame: 6 size: 0
skipping frame: 7 size: 0
skipping frame: 8 size: 0
skipping frame: 9 size: 0
skipping frame: 10 size: 0
skipping frame: 11 size: 0
skipping frame: 12 size: 0
skipping frame: 13 size: 0
skipping frame: 14 size: 0
skipping frame: 15 size: 0
skipping frame: 16 size: 0
skipping frame: 17 size: 0
skipping frame: 18 size: 0
skipping frame: 19 size: 0
skipping frame: 20 size: 0
skipping frame: 21 size: 0
skipping frame: 22 size: 0
skipping frame: 23 size: 0
skipping frame: 24 size: 0
skipping frame: 25 size: 0
skipping frame: 26 size: 0
skipping frame: 27 size: 0
skipping frame: 28 size: 0
skipping frame: 29 size: 0
skipping frame: 30 size: 0
skipping frame: 31 size: 0
skipping frame: 32 size: 0
skipping frame: 33 size: 0
skipping frame: 34 size: 0
skipping frame: 35 size: 0
skipping frame: 36 size: 0
[LavFormat] Bitrate 128
[lavc] Output #0, mp4, to 'C:\test.mp4':

[lavc] Stream #0.0
[lavc] : Video: 0x0000, 720x576, q=2-31, 2000 kb/s
[lavc] , 25.00 fps(c)
[lavc]

[lavc] Stream #0.1
[lavc] : Audio: 0x0000, 44100 Hz, stereo, 128 kb/s
[lavc]

lavformat mpeg muxer initialized
LavMuxer:Audio DTS is too low 0 / 0!
LavMuxer:Audio DTS is too low 0 / 0!
LavMuxer:Audio DTS is too low 23219 / 0!
2nd pass, sent 108 frames
Waiting Audio thread
[AudioQueueThread] Aborting..
[AudioQueueThread] Exiting
[AudioThread] Target 4294901760, got 126976, 0.000030 %
x264 [info]: slice I:1 Avg QP:15.98 size: 45189 PSNR Mean Y:46.26 U:47.11 V:47.82 Avg:46.62 Global:46.62
x264 [info]: slice P:32 Avg QP:22.06 size: 16124 PSNR Mean Y:41.67 U:43.93 V:45.13 Avg:42.42 Global:42.32
x264 [info]: slice B:39 Avg QP:25.75 size: 7483 PSNR Mean Y:40.36 U:43.09 V:44.31 Avg:41.20 Global:41.09
x264 [info]: consecutive B-frames: 4.2% 56.3% 33.8% 5.6% 0.0% 0.0% 0.0% 0.0% 0.0%
x264 [info]: mb I I16..4: 30.4% 64.0% 5.7%
x264 [info]: mb P I16..4: 4.9% 21.3% 1.7% P16..4: 47.9% 12.6% 4.9% 0.1% 0.1% skip: 6.5%
x264 [info]: mb B I16..4: 0.3% 3.1% 0.4% B16..8: 38.4% 3.1% 3.2% direct: 7.1% skip:44.3% L0:42.4% L1:50.3% BI: 7.4%
x264 [info]: 8x8 transform intra:76.0% inter:83.8%
x264 [info]: direct mvs spatial:89.7% temporal:10.3%
x264 [info]: ref P L0 57.0% 15.2% 9.3% 4.3% 3.8% 3.1% 2.6% 1.7% 1.4% 1.6%
x264 [info]: ref B L0 79.7% 8.4% 4.0% 2.2% 1.8% 1.2% 1.3% 0.9% 0.6%
x264 [info]: ref B L1 96.8% 3.2%
x264 [info]: SSIM Mean Y:0.9720417
x264 [info]: PSNR Mean Y:41.028 U:43.517 V:44.726 Avg:41.818 Global:41.645 kb/s:2369.45
[Bridge] Destroying bridge
[FAAC] Deleting faac
[lavc] Killing decoding threads
[lavc] Destroyed
Deleting post proc
Cleaning up
Waiting for Spidermonkey to finish...
Cleaning up Spidermonkey.
[SDL] Quitting...
End of cleanup

Images stat:
___________
Max memory consumed (MB) : 8505
Current memory consumed (MB) : 0
Max image used : 15
Cur image used : 0
Global mem stat
______________
Memory consumed: 3 (MB)

Goodbye...

I used "as input" PAR, which is 16:15 in this case. The result plays with proper 4:3 aspect ratio in MPlayer:

VO: [gl] 720x576 => 768x576 BGRA [zoom]

[Pulstar]

I forgot to mention they're MPEG1's ;) well I checked the MP4 files using a hex editor and the header/footer is identical in all files. Played them in MPC, Nokia MP and WMP (using Gabest's MP4 splitter) and they play back fine. Perhaps the error message is related to the funky embedded aspect ratios that AVIDemux says it can't discern in certain MPEG1s? Anyway thanks for your help and AVIDemux is awesome :)