Newest 'ffmpeg' Questions - Stack Overflow

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• ffmpeg decode multiple streams at same time

  29 février 2012, par broschb

  I am using ffmpeg to decode a file and play it back on an android device. I have this working and would now like to decode two streams at the same time. I have read some comments regarding needing to use av_lockmgr_register() call with ffmpeg, unfortunately I am not sure how to use these and how the flow would work when using these locks.

  Currently I have seperate threads on the java side making requests through JNI to native code that is communicating with ffmpeg.

  Do the threads need to be on the native(NDK) side, or can I manage them on the java side? And do I need to do any locking, and if so how does that work with ffmpeg?

  ***UPDATE I have this working now, it appears that setting up the threads at the java sdk level transfers into separate threads at the native level. With that I was able to create a struct with my variables, and then pass a variable to the native layer to specify what struct to use for each video. So for I have needed to use any mutexs or locks at the native level, and haven't had any issues.

  Does anyone know of potential gotchas I may encounter by not doing so with ffmpeg?

• Resize video using FFmpeg C API

  28 février 2012, par cr_az

  I am trying to resize video file on Android device using FFmpeg. Remark: I cant use FFmpeg as binary - in my case it should be used as shared library (only FFmpeg C API is accessible).

  I did not find any documentation regarding video resizing, however it looks like algorithm is following:

  10 OPEN video_stream FROM video.mp4
  20 READ packet FROM video_stream INTO frame
  30 IF frame NOT COMPLETE GOTO 20
  40 RESIZE frame
  50 WRITE frame TO converted_video.mp4
  60 GOTO 20
  

  Should I use sws_scale function in order to resize frame? Is there any other (easier?) way to resize video file using FFmpeg C API?

• streaming camera captured video to another location

  28 février 2012, par Fei Su

  I am using Kinect camera capture images and compress them to video and save the video into the disk(python opencv). How can I stream and display it at another location? Because the video is made at real-time and I also need to display and stream it in real time.

• ffmpeg invalid data found when processing input

  28 février 2012, par user1222905

  I did download the .tar.gz for ffmpeg 0.10. I am trying to convert a file called message.h263 to output.mp4. I did: "ffmpeg -i message.h263 -vcodec libx264 -acodec libfaac -f mov out.mp4" the result I get is:

  ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
    built on Feb 28 2012 15:11:37 with gcc 4.4.5
    configuration: 
    libavutil      51. 34.101 / 51. 34.101
    libavcodec     53. 60.100 / 53. 60.100
    libavformat    53. 31.100 / 53. 31.100
    libavdevice    53.  4.100 / 53.  4.100
    libavfilter     2. 60.100 /  2. 60.100
    libswscale      2.  1.100 /  2.  1.100
    libswresample   0.  6.100 /  0.  6.100
  message.h263: Invalid data found when processing input
  

  HOW TO SOLVE THIS? I am new to this stuff and i can;t seem to get it out. I spend all my day solving this with no result. I am working under Ubuntu 10.10. Need help. Thx appreciate.

• Create DVD-Video Menu's with ff-mpeg

  28 février 2012, par Bat Masterson

  Is it possible to create a DVD-Video Menu with ff-mpeg only ?

  I may be misunderstanding but I don't think that ff-mpeg alone is capable of creating a dvd menu.

  I've found some examples using ff-mpeg and various other tools but nothing solely ff-mpeg. The other tools are all linux and I'm stuck in windows.

  If someone would clear that up for me that would be great. Also if you know of a library for creating dvd menus or a command line utility would also help.

  Thanks In Advance