December 2008 - ffmpeg-user - lists.ffmpeg.org

DivX and MPEG-4 Part 2
by mpeg.blue＠free.fr 18 Dec '08

18 Dec '08

Hello, What is the history of the DivX codec ? http://en.wikipedia.org/wiki/DivX http://en.wikipedia.org/wiki/Xvid http://forum.doom9.org/showthread.php?t=74070 $ grep "'D', 'I', 'V'" riff.c { CODEC_ID_MPEG4, MKTAG('D', 'I', 'V', 'X') }, { CODEC_ID_MPEG4, MKTAG('D', 'I', 'V', '1') }, { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '3') }, { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '5') }, { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '6') }, { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '4') }, { CODEC_ID_MSMPEG4V2, MKTAG('D', 'I', 'V', '2') }, CODEC_ID_MPEG4 is "plain" MPEG-4 ASP, right ? While CODEC_ID_MSMPEG4V3 is Microsoft's "fork" of MPEG-4 ASP ? http://wiki.multimedia.cx/index.php?title=Microsoft_MPEG-4 http://svn.mplayerhq.hu/michael/trunk/docs/msmpeg4.txt?view=co I imagine that "plain" MPEG-4 ASP decoders cannot decode MSMPEG4V3 streams ? Did DivX start as a standard MPEG-4 ASP codec ("DIVX", "DIV1") only to later adopt MSMPEG4V3 ? (That doesn't sound right.) What are "DIVX" and "DIV1" ? The answer might be : http://wiki.multimedia.cx/index.php?title=MPEG-4 """ libavcodec [...] used to set the FourCC to 'DIVX' when encoding MPEG-4 videos (the FourCC is an AVI tag to identify the software used to encode and the intended software to use for decoding the video). This led many people to think that libavcodec was a DivX encoding library, when in fact it is a completely different MPEG-4 encoding library which implements the MPEG-4 standard much better than DivX does. Therefore, the new default FourCC used by libavcodec is 'FMP4' [...] DIVX FourCC means DivX4, which is a very basic MPEG-4 codec, whereas DX50 and XVID both mean full MPEG-4 (ASP). Therefore, if you change the FourCC to DIVX, some bad software or hardware players may choke on some advanced features that libavcodec supports, but DivX doesn't; on the other hand XviD is closer to libavcodec in terms of functionality, and is supported by all decent players. """ If DIVX means DivX4, then what does DIV4 mean ? $ grep "'V', 'I', 'D'" riff.c { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, { CODEC_ID_MPEG4, MKTAG('V', 'I', 'D', 'M') }, Is Xvid a "standard" MPEG-4 ASP codec ? I thought Xvid was a fork of DivX encore2 ? Isn't encore2 an MSMPEG4V2 codec ? Thanks to all who can clear some of my confusion :-) -- Regards.

2 6

Problem with wmv3 video embedded in quicktime container
by chris＠marrin.com 18 Dec '08

18 Dec '08

I have a .wmv file, which is an ASF container with WMV3 video and WMA2 audio. I can open this in the Quicktime player and it plays fine, thanks presumably to Flip4Mac. Now I trim out a small section and do a Save As..., which saves the clip as a .mov file. Looking at this, the video format is still WMV3, but the container format is now quicktime rather than ASF. This file still opens and plays fine in Quicktime player. But when I try this: ffmpeg -i foo.mov foo.mp4 I get the following: [mov,mp4,m4a,3gp,3g2,mj2 @ 0x1002600]edit list not starting at 0, a/v desync might occur, patch welcome [mov,mp4,m4a,3gp,3g2,mj2 @ 0x1002600]edit list not starting at 0, a/v desync might occur, patch welcome Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'foo.mov': Duration: 00:00:07.04, start: 0.000000, bitrate: 16570 kb/s Stream #0.0(eng): Audio: wmav2, 48000 Hz, stereo, s16 Stream #0.1(eng): Video: wmv3, 1440x1080, 25.00 tb(r) FFmpeg version SVN-r15883, Copyright (c) 2000-2008 Fabrice Bellard, et al. configuration: --disable-ffplay --disable-ffserver --enable-gpl -- enable-postproc --enable-swscale --enable-avfilter --enable-avfilter- lavf --disable-vhook --enable-libfaac --enable-libfaad --enable- libmp3lame --enable-libvorbis --enable-libtheora --enable-libx264 -- enable-libxvid libavutil 49.12. 0 / 49.12. 0 libavcodec 52. 3. 0 / 52. 3. 0 libavformat 52.23. 1 / 52.23. 1 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 1. 0 / 0. 1. 0 libswscale 0. 6. 1 / 0. 6. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Nov 27 2008 11:25:57, gcc: 4.0.1 (Apple Inc. build 5490) swScaler: Unknown format is not supported as input pixel format Cannot get resampling context Notice that it understands that the input video is wmv3, so all seems ok there. When I do the same, using the .wmv file as input, it works fine. And here is the spew I see: Seems stream 1 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 25.00 (25/1) Input #0, asf, from 'seaturtle_hd.wmv': Duration: 00:00:58.45, start: 3.000000, bitrate: 9632 kb/s Stream #0.0: Audio: wmav2, 48000 Hz, stereo, s16, 128 kb/s Stream #0.1: Video: wmv3, yuv420p, 1440x1080, 9000 kb/s, 25.00 tb(r) FFmpeg version SVN-r15883, Copyright (c) 2000-2008 Fabrice Bellard, et al. configuration: --disable-ffplay --disable-ffserver --enable-gpl -- enable-postproc --enable-swscale --enable-avfilter --enable-avfilter- lavf --disable-vhook --enable-libfaac --enable-libfaad --enable- libmp3lame --enable-libvorbis --enable-libtheora --enable-libx264 -- enable-libxvid libavutil 49.12. 0 / 49.12. 0 libavcodec 52. 3. 0 / 52. 3. 0 libavformat 52.23. 1 / 52.23. 1 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 1. 0 / 0. 1. 0 libswscale 0. 6. 1 / 0. 6. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Nov 27 2008 11:25:57, gcc: 4.0.1 (Apple Inc. build 5490) Output #0, mp4, to 'foo.mp4': Stream #0.0: Video: mpeg4, yuv420p, 1440x1080, q=2-31, 9000 kb/s, 25.00 tb(c) Stream #0.1: Audio: libfaac, 48000 Hz, stereo, s16, 64 kb/s Stream mapping: Stream #0.1 -> #0.0 Stream #0.0 -> #0.1 Press [q] to stop encoding frame= 28 fps= 21 q=7.5 Lsize= 1463kB time=1.12 bitrate=10701.9kbits/s video:1462kB audio:0kB global headers:0kB muxing overhead 0.059705% I find it odd that, in the first case, the input video line makes no mention that the pixel format is yuv420p, so maybe that is what swScaler is complaining about. I've tried adding '-pix_fmt yuv420p' to both the input and output sides, but that doesn't seem to make any difference. Is there some option I'm missing? Or is this a bug in ffmpeg? Or is it maybe a problem in quicktime saving the file in the first place? Seems like even if quicktime (or Flip4mac) is deficient, ffmpeg should be able to deal with it, since quicktime can open and understand the file. Any clues would be very helpful. ----- ~Chris chris at marrin.com

1 0

MJPEG quality?
by mark＠image-engine.com 18 Dec '08

18 Dec '08

Hi, I'm struggling to find the simplest of controls amongst all of those given by "ffmpeg -help". I have a JPEG image sequence which I'd like to encode as an MJPEG Quicktime, in the highest quality possible. The source image files are the same resolution as the desired movie file, and I've tried experimenting with various flags such as "-b" (bitrate), "-sameq", "-intra", but it seems no matter what I do the resultant MJPEG file is very small in comparison to the total size of all the JPEGs ( about 30% the size ), and the quality is very poor - with heavy macroblocking in places. This is an example of the commandline I'm using: ffmpeg -y -f image2 -r 24 -i input.%04d.jpg -intra -sameq -vcodec "mjpeg" output.mov Any help appreciated. Thanks in advance, Mark

3 3

AAC - CBR
by mgberry＠ellipticity.com 18 Dec '08

18 Dec '08

For the life of me I cant figure out what option is used to force libfaac to CBR in ffmpeg. Any help would be great! -Matt

1 0

Fast decoding of h264 files, how to skip B Frames
by jm＠poure.com 17 Dec '08

17 Dec '08

On Wed, 2008-12-17 at 15:20 +0100, Michael Niedermayer wrote: > also try -flags2 +fast which should provide a little more speed at the > expense of possible artifacts, and keep in mind you can maybe skip B > frames to speed things up further. How can I skip B-frames during reading h264 files? I need fast decoding of h264 files, without any need for quality. Kind regards, Jean-Michel

2 1

[Kdenlive-devel] AVCHD/h264 decoding benchmarking
by jm＠poure.com 17 Dec '08

17 Dec '08

On Wed, 2008-12-17 at 10:43 -0800, Dan Dennedy wrote: > configure with --enable-pthreads and run ffplay with the -threads > option followed by the number of worker threads to use. It will still > keep a decoder control thread and separate reader/output threads, all > of which are fairly light, so it is a good idea to use (#cores - 1) > for the worker threads. Ah ... this skiploop is not documented. ffplay -skiploop 48 -threads 2 avchd-test-1.mts works very well. By the way, FFmpeg developers suggested that we do not decode B frames during viewing. I don't know is this can apply to Kdenlive. So Kdenlive is really AVCHD compliant. Good news. I am really pleased. Thanks. Jean-Michel

1 0

pts < dts file read error, BBCHD mpegts
by belcampo＠zonnet.nl 17 Dec '08

17 Dec '08

FFmpeg version SVN-r16188, Copyright (c) 2000-2008 Fabrice Bellard, et al. configuration: --prefix=/usr --enable-gpl --enable-libfaac libavutil 49.12. 0 / 49.12. 0 libavcodec 52. 7. 0 / 52. 7. 0 libavformat 52.23. 1 / 52.23. 1 libavdevice 52. 1. 0 / 52. 1. 0 built on Dec 17 2008 18:18:40, gcc: 4.2.2 20071128 (prerelease) (4.2.2-3.1mdv2008.0) I get [NULL @ 0x8a15330]error, pts < dts av_interleaved_write_frame(): Error while opening file Searched the dev-list, and in 2008-March-19 there is some talk of mpegts-demuxer gives wrong pts/dts with avchd files Is this the same or another problem ? With FFmpeg version SVN-r12547, Copyright (c) 2000-2008 Fabrice Bellard, et al. configuration: --prefix=/usr --enable-libx264 --enable-libxvid --enable-gpl --enable-libfaac --enable-libfaad --enable-postproc --enable-libmp3lame --enable-libvorbis --enable-pthreads libavutil version: 49.6.0 libavcodec version: 51.53.0 libavformat version: 52.12.0 libavdevice version: 52.0.0 and following patch to ffmpeg.c ------- ffmpeg.c.diff --- ffmpeg.c 2007-12-17 21:47:23.000000000 +0100 +++ ffmpeg.c 2007-12-17 21:50:13.000000000 +0100 @@ -406,8 +406,6 @@ } static void write_frame(AVFormatContext *s, AVPacket *pkt, AVCodecContext *avctx, AVBitStreamFilterContext *bsfc){ - int ret; - while(bsfc){ AVPacket new_pkt= *pkt; int a= av_bitstream_filter_filter(bsfc, avctx, NULL, @@ -423,11 +421,7 @@ bsfc= bsfc->next; } - ret= av_interleaved_write_frame(s, pkt); - if(ret < 0){ - print_error("av_interleaved_write_frame()", ret); - exit(1); - } + av_interleaved_write_frame(s, pkt); } #define MAX_AUDIO_PACKET_SIZE (128 * 1024) ----------------- I don't have this problem. Henk Schoneveld

1 0

Compile problems SVN 16187 as of today
by belcampo＠zonnet.nl 17 Dec '08

17 Dec '08

Trying to compile latest from SVN make distclean;./configure --prefix=/usr --enable-gpl;make results in: ----- libavformat/framehook.h:25:2: warning: #warning VHOOK is deprecated. Please help finishing libavfilter instead of wasting your time writing new filters for this crappy filter system. ffmpeg.c: In function ?write_frame?: ffmpeg.c:509: error: ?ret? undeclared (first use in this function) ffmpeg.c:509: error: (Each undeclared identifier is reported only once ffmpeg.c:509: error: for each function it appears in.) make: *** [ffmpeg.o] Error 1 Anybody any idea What could be the cause Henk Schoneveld

1 1

AVCHD/h264 decoding benchmarking
by jm＠poure.com 17 Dec '08

17 Dec '08

Dear Friends, For http://www.kdenlive.org project, I am trying to determine the hardware requirements to decode h264/AVCHD interactively. When using AVCHD camcorder, we would like to inform end-users of hardware requirements. I know hardware acceleration is coming along with Nvidia VDPAU patch that we ***may*** implement in MLT, depending on development resources. Until then, we rely entirely on FFmpeg optimisations and multithreading. My questions: * Is anyone with a dual-core/quad-core computer able to decode one of these movies interactively: http://www.kdenlive.org/videos/avchd-test-1.mts http://www.kdenlive.org/videos/avchd-test-2.mts http://www.kdenlive.org/videos/avchd-test-3.mts http://www.kdenlive.org/videos/avchd-test-4.mts http://www.kdenlive.org/videos/avchd-test-5.mts These files come out a HD AVCHD camcorder. Use ffplay to test. If one movie plays in slow motion, others will. No need to test everything. My dual-core computer is not able to decode interectively any of these movies. * Does h264 and AVCHD use sliced decoding which I saw in SVN? Is h264 decoding really multi-threaded? When using ffplay, I see only one core working at 100%. How to activate multi-threading decoding. Can we expect to decode AVCHD with a quad-core? Thank you for your answers. According to your information, we will publish information on kdenlive web site. Kind regards, Jean-Michel

3 2

qt-faststart very slow
by evert＠rooftopsolutions.nl 17 Dec '08

17 Dec '08

Hey guys, We're running an automated transcoder daemon using FFMpeg. We're also using qt-faststart to move the MOOV atom to the beginning of our H264 files. In certain cases this however runs extremely slow. Just getting into the office I noticed one of them running for about 12 hours, for a relatively small file.. Are there known bugs with this tool (possibly with slightly corrupted files?) Is anyone aware of alternative tools that achieve the same thing? Thanks very much, Evert

5 13