November 2012 - ffmpeg-user - lists.ffmpeg.org

Combining multiple MP3's?
by Gilles 03 Mar '14

03 Mar '14

3 2

AC3 encoding problem - wrong audio tag?
by Stefan Gofferje 14 Jan '14

14 Jan '14

Hi, I have recently changed my home video editing to Linux (kdenlive) to get finally completely rid of Windows. Now I'm trying to encode some home-video with ac3 sound. I do the testing/playing with a Pinnacle Showcenter network media player which is connected via fiber-optic cable to a Haman Kardon amplifier. When I play my the encoded file, the amp show "Dolby 2/0" and is silent. The Showcenter shows as audio type "Ogg". File shows RIFF (little-endian) data, AVI, 624 x 352, 23.98 fps, video: XviD, audio: (6 channels, 48000 Hz) If I check older files that work on the Showcenter, the output of file is: RIFF (little-endian) data, AVI, 624 x 352, 23.98 fps, video: XviD, audio: Dolby AC3 (stereo, 48000 Hz) So in my encoding, the "Dolby AC3" tag seems to be missing. I use ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers built on Jun 15 2012 15:33:11 with gcc 4.5.1 20101208 [gcc-4_5-branch revision 167585] configuration: --prefix=/usr --mandir=/usr/share/man --libdir=/usr/lib64 --shlibdir=/usr/lib64 --disable-stripping --enable-pthreads --enable-shared --enable-avfilter --disable-static --enable-libfaac --enable-libmp3lame --enable-libxvid --enable-libx264 --enable-nonfree --enable-postproc --enable-shared --enable-libdc1394 --enable-libtheora --enable-libschroedinger --enable-libvpx --enable-gpl --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-version3 --enable-x11grab libavutil 51. 54.100 / 51. 54.100 libavcodec 54. 23.100 / 54. 23.100 libavformat 54. 6.100 / 54. 6.100 libavdevice 54. 0.100 / 54. 0.100 libavfilter 2. 77.100 / 2. 77.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 and my command-line is like ffmpeg -i video.mp4 -i left.wav -i right.wav -i surr_left.wav -i surr_right.wav -i center-wav -i lfe-wav -vcodec libxvid -s 624x352 -b:v 1100k -acodec ac3 -ar 48000 -ab 448k video.avi Any hints? -Stefan -- (o_ Stefan Gofferje | SCLT, MCP, CCSA //\ Reg'd Linux User #247167 | VCP #2263 V_/_ Heckler & Koch - the original point and click interface -------------------------------------------------------------------------------- This mail was scanned for malware by ClamAV (http://www.clamav.net/) --------------------------------------------------------------------------------

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meaning of macroblock colors when using vis_mb_type option
by Wesley S. 29 Dec '13

29 Dec '13

Hi, I was wondering what all the different macroblock colors meant when using the vis_mb_type option? Kind regards, Wesley

6 6

x11grab video stalls every 30 seconds in screencapture
by Troy Gardner 11 Dec '13

11 Dec '13

We are using latest ffmpeg, for screencapture in the cloud. We are seeing odd dropped frame stalls in video capture every 30 seconds for about 1-2 seconds in duration. Audio is captured without stalls, and Audio Video sync is perfectly fine despite stalls. Hoping someone had ideas, this is driving us nuts and there's nothing obvious to explain it. This is the capture setting we are using. ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1024x768 -i :0.0 -acodec libvorbis -ar 44100 -vcodec libx264 -preset ultrafast -gp 0 -threads 0 ffg4.mkv This is the a drop frame test case capture with lossless x264 that shows dropped frames around 25-26 and significant stall errors at 30 and 60 seconds http://66.220.0.170/XFG4.mkv We get this trying different options, like keyframes. This is the output with flashsrv, which shows similar pause around 23 and 53 seconds, and indicates it's not a libx264 specific issue. flashsrv http://66.220.0.170/out.mov This is running on an instance with 16 vcpu + 16gb ram, on the Amazon AWS there is no noticeable background process that we can see at least that would explaing and happens regardless if it's debian, or ubuntu. This is the version of ffmpeg. ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers built on Jun 26 2012 12:42:06 with gcc 4.7.1 configuration: --arch=x86_64 --enable-avfilter --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static --enable-libx264 --enable-libvpx --enable-libmp3lame --enable-libfaac --enable-nonfree --enable-libopencore-amrwb --enable-libopencore-amrnb --enable-version3

7 10

feature request: able to link against libjpeg
by Roger Pack 14 Nov '13

14 Nov '13

Hello. I suppose that ffmpeg has its own "internal" jpeg library for decoding/encoding jpeg's. My assumption is also that it is "unoptimized" (at least compared to similar libraries, like libjpeg-turbo). My wish/goal would be to have the speed of libjpeg-turbo. Maybe a configure option to use libjpeg instead of the internal stuff? Thoughts? Thanks. -r

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How do I make ffplay play without high latency?
by Jesse Gordon 15 Oct '13

15 Oct '13

Good Day, I have an internet-controllable robot (See photo) and I have a little Cisco MP4 streaming video network camera on it, and I'm trying to use ffplay to play the live video stream. The camera encodes the video to either mjpeg or mpeg4 with extremely low latency. I'm using the mpeg4 mode because it requires far less bandwidth. The problem I'm having is that ffplay seems to introduce a second or two of latency -- which is a big deal when you're driving the robot via the video feed, and you can' t see where you're going until after it's too late. With mplayer I was using the -benchmark option which makes it play as fast as possible, but even that has just under a second of latency. I know that the video camera is getting the data out the network port quickly because when I use the windows web client, it has a plugin that streams/plays the mpeg4 and it has very low latency -- so I know the camera is not the source of the latency. (But of course I use Linux.) Is there a way to make ffmpeg play each frame as soon as it can with reduced buffers or whatever so I can get the picture to the screen as soon as possible? I don't care too much about jitter or stuttering - I just need the video on the screen as soon as possible. Thank you very much, ~Jesse NOTE: Below, the "warning: first frame is no keyframe" line happened when I clicked in ffplay to fast forward to the end, to try to get latency to reduce. But the video was playing just fine after I clicked to fast forward. bash-4.1# ffplay http://admin:admin@192.168.0.65/img/video.asf ffplay version N-46939-g030db0c Copyright (c) 2003-2012 the FFmpeg developers built on Nov 21 2012 00:52:42 with gcc 4.5.2 (GCC) configuration: --prefix=/usr libavutil 52. 8.100 / 52. 8.100 libavcodec 54. 74.100 / 54. 74.100 libavformat 54. 37.100 / 54. 37.100 libavdevice 54. 3.100 / 54. 3.100 libavfilter 3. 23.101 / 3. 23.101 libswscale 2. 1.102 / 2. 1.102 libswresample 0. 17.101 / 0. 17.101 [asf @ 0x8f2b1a0] Estimating duration from bitrate, this may be inaccurate Input #0, asf, from 'http://admin:admin@192.168.0.65/img/video.asf': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: mpeg4 (MP4S / 0x5334504D), yuv420p, 640x480, 14.99 tbr, 1k tbn, 1k tbc Frame changed from size:0x0 to size:640x480 4KB sq= 0B f=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 972, new 874=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 972, new 829=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 971, new 823=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 975, new 11230/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 974, new 14450/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 974, new 753=0/0 [mpeg4 @ 0x8f40920] warning: first frame is no keyframe 0KB sq= 0B f=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 973, new 790=0/0 B f=0/0 [asf @ 0x8f2b1a0] freeing incomplete packet size 975, new 784=0/0 61.58 A-V: 0.000 fd= 517 aq= 0KB vq= 0KB sq= 0B f=0/0 bash-4.1#

6 28

Encoding x264 hangs in a high turn over pipeline
by Luke 06 Oct '13

06 Oct '13

Hello, We are testing ffmpeg in our compression pipeline as our commercial software does not provide the functionality we need. We run a multithreaded compression (ffmpeg multithreading isn't used, our own solution is) using the following command: ffmpeg -i #input# -f mp4 -vcodec libx264 -s 1024x576 -b:v 2000k -g 33 -acodec libmp3lame -b:a 128k -ar 44100 -vf "movie=#logo# [wm]; [in][wm] overlay=10:main_h-overlay_h-10 [out]" -y #output# Approx. 75% threads complete without any problems, the remaining ones get stuck - cpu usage on each thread drops to 0, memory usage gets stuck at around 300MB. Initially we used aac and libvo_aacenc coders for audio, but the hangs seemed more frequent. Tested on a few recent ffmpeg builds, including the one compiled on 20/07. Any help would be greatly appreciated. Many thanks, Luke -- *Luke Niejadlik* Audiomotion Studios Ltd. T: +44 (0)8701 600 504 F: +44 (0)1865 725 651 www.audiomotion.com <http://www.audiomotion.com/> Develop Awards - Best Services Winner 2011, 2009 & 2004 */JOIN THE MOVEMENT!/* - www.facebook.com/audiomotion.studios <http://www.facebook.com/audiomotion.studios> - twitter.com/audiomotion <http://twitter.com/audiomotion> - http://www.join-the-movement.co.uk/

5 8

UDP Multicast streaming
by omar.gomez＠gmail.com 04 Oct '13

04 Oct '13

Hi!, I've been using the FFmpeg + Mplayer combo for a college project I'm working on. The idea is to stream an Opengl app's buffer is real-time in order to have thin-clients interact remotely with the app. I've succeed at building an scenario where the buffer is pulled out of the app and injected to a pipe using the following command: cat <fifo> | ppmtoy4m -S 420jpeg | ffmpeg -y -f yuv4mpegpipe -i - -f avi udp:127.0.0.1:1234 Clients then use the following command to view the stream: mplayer -demuxer mpeg4es udp://@127.0.0.1:5000 This has been working all right, but I want to achieve the following: 1) Work in a multicast scenario. ======================== I though it was as easy as to change the address for a multicasting one like the following: cat <fifo> | ppmtoy4m -S 420jpeg | ffmpeg -y -f yuv4mpegpipe -i - -f avi udp:224.0.0.1:5000?ttl=1 Using the ?ttl parameter was something I found by googling, but I'm not sure if that works. At the same time MPLayer clients should work by using: mplayer -demuxer mpeg4es udp://@224.0.0.1:5000 Which works, but I'm wondering why I *have* to add a port (being a multicast address) and why it doesn't work if I open a second client (I believe is still working as unicast) 2) Using VLC ========== I've not been able to make this work with VLC. That "demuxer" parameter seen to be the problem. 3) Use different containers,codecs ================== This seems to be working using mpeg4+yuv420p. I would like to experiment with other codes as well, like h263p or h262. Have any of you have had one of these problems? I appreciate any help --Omar -- Follow me at: Twitter: http://twitter.com/omargomez Buzz: http://www.google.com/profiles/108165850309051561506#buzz Blog: blog.pixagora.com

2 1

compile error: ffmpeg av_get_default_channel_layout
by Sven Dueking 06 Sep '13

06 Sep '13

Hi all, I am not a linux expert, maybe I made something stupied but I was not able to figure out what´s wrong here. Basically I downloaded ffmpeg 11.0, build it and set the lib and include path in eclipse. But I get this error : relocation error: /usr/local/lib/libavcodec.so.54: symbol av_get_default_channel_layout, version LIBAVUTIL_51 not defined in file libavutil.so.51 with link time reference My guess is, there is a mismatch between older and newer libs from ffmpeg. Can anyone help here ? Not sure if this makes a difference, the same code works under windows. Thanks, Sven

6 11

Extracting MXF Metadata
by hsomob1999＠yahoo.com 02 Sep '13

02 Sep '13

Hello, Is it possible to retrieve MXF metadata with ffmpeg? Is there way to extract metadata from any format? I see that there is a -metadata flag but this only allows one to set metadata. Thanks

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