Newest 'ffmpeg' Questions - Stack Overflow

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• (Cross-platform) FFMPEG based GUI direct stream copy linear video editor [on hold]

  14 octobre 2014, par Fluorescent Hallucinogen

  FFMPEG official site has list of FFMPEG based projects (https://trac.ffmpeg.org/wiki/Projects).

  I use VirtualDub for linear video montage using direct stream copy mode (without recompression). It is GNU GPL licensed, but is designed only for Microsoft Windows and operates only AVI files.

  FFMPEG is excellent cross-platform utility that supports many formats (codecs and containers). It can be used for split and merge video files (not only AVI) using direct stream copy mode, but FFMPEG is console UI application.

  Is there GUI video editor (based on FFMPEG) (cross-platform or maybe only for Linux or maybe only for Windows) that can split and merge video files (not only AVI) using direct stream copy mode and have preview window?

  Now I use video player, watch the input video file, remember the time for split video to fragments and write console line script for merge these fragments. All work is OK, but it is very inconvenient.

  At the worst, are there players or editors that can generate project file (that contains time markers for split and merge) that can be used with FFMPEG?

• How to record video with audio using ffmpeg and upload live to server by hls on android ?

  14 octobre 2014, par dphdjy

  I want to create a video with audio using ffmpeg and upload live to server from Android Camera.

  I find some codes about this.

  1. The kickflip SDK requires Android 4.3+.
  2. FFmpegTest requires Android 4.1+.

  Now,How to get .ts files from Camera.

  Thanks.

• iOS - How to hardware accelerate MKV (+ others unsupported) playing

  14 octobre 2014, par awfulcode

  I saw that a few video players (e.g. AVPlayerHD) are doing hardware-accelerated playing on iOS for unsupported containers like MKV. How do you think they're achieving that?

  I'm thinking reading packet with ffmpeg, decoding with Core Video. Does that make sense? I'm trying to achieve the same.

  Thanks!

• FFmpeg using avcodec_decode_audio4 to decode an audio frame failed

  14 octobre 2014, par Jeff Chen

  well,I'm learning FFmpeg APIs recently.And I want to get a *.MP4 file's audio frames but failed. My coding is :

  int pktSize = packet->size;  
  while (pktSize > 0) {  
      avcodec_get_frame_defaults(self.av_Context->pAudioFrame);  
      int gotframe = 0;   
      int len = avcodec_decode_audio4(self.av_Context->pAudioCodecCtx, self.av_Context->pAudioFrame, &gotframe, packet);  
      if (len < 0) {  
          char buffer[1024];  
          av_strerror(len, buffer, 1024);  
          NSLog(@"decode audio error,error:%d(%s)",len,buffer);  
          break;  
      }  
      if (gotframe) {  
          NSLog(@"got a audio frame");  
          KxAudioFrame *frame = [self handleAudioFrame:self.av_Context->pAudioFrame];  
          if (frame) {  
              [self.audioFrames addObject:frame];  
              NSLog(@"self.audioFrames.count = %d++",self.audioFrames.count);  
          }  
      }  
      if (len == 0) {  
          break;  
      }  
      pktSize -= len;
  }    
  

  the len always return -22,anyone knows why?please tell me the answer,thanks very much!

• Convert RTP packets to WAV or AU using ffmpeg

  14 octobre 2014, par Jonas Kongslund

  I have a file containing a sequence of RTP packets wrapped in UDP/IP packets. I want to convert this file to a WAV or AU file and was told that ffmpeg may be able to do the job. However the tool does not behave as I would expect. For some reason it is expecting an SDP file but I do not have such a file and I am wondering why it is needed since the RTP packets seem to contain enough information in order to do the conversion. Also it is reporting the wrong payload type.

  Any ideas? Below is what I have tried. The RTP packets in the input file alaw.rtp only have payload types 8 (A-law) and 72 (RTCP related) so I do not know where payload type 105 is coming from.

  $ ffmpeg -f rtp -i alaw.rtp alaw.au
  ...
  [rtp @ 0x9dbdfe0] Unsupported RTP version packet received
      Last message repeated 89 times
  [rtp @ 0x9dbdfe0] Unable to receive RTP payload type 105 without an SDP file describing it
  [rtp @ 0x9dbdfe0] Estimating duration from bitrate, this may be inaccurate
  Input #0, rtp, from 'alaw.rtp':
    Duration: N/A, bitrate: N/A
  File 'alaw.au' already exists. Overwrite ? [y/N] y
  Output #0, au, to 'alaw.au':
  Output file #0 does not contain any stream
  

  This is the version of ffmpeg that I have used

  ffmpeg version 0.10.6-6:0.10.6-0ubuntu0jon1~lucid2
  built on Nov 12 2012 15:20:22 with gcc 4.4.3