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• Decoding Video using FFMpeg for android

  29 novembre 2014, par Rahul Upadhyay

  I tried to decode video using FFMpeg library from the sample examples available on internet, i figure it out with new version of ffmpeg,
  here is the code which I called from my class file,

     private static native int decodeVideo(String filename);
  
     decodeVideo(getString(R.string._sdcard_abc_3gp));

  now in .c file located in JNI dir,I wrote this code,

   jint Java_ru_dzakhov_ffmpeg_test_MainActivity_decodeVideo(JNIEnv* env, jobject
  
  javaThis,jstring filename) {   
  
    AVFormatContext *pFormatCtx;
  
    int             i, videoStream;
  
    AVCodecContext  *pCodecCtx;
  
    AVCodec         *pCodec;
  
    AVFrame         *pFrame;
  
    AVFrame         *pFrameRGB;
  
    AVPacket        packet;
  
    int             frameFinished;
  
    int             numBytes;
  
    uint8_t         *buffer;
  
  
  
    // Register all formats and codecs
  
    av_register_all();
  
  
  
    // Open video file
  
  
  
        const jbyte *str;
  
        str = (*env)->GetStringUTFChars(env, filename, NULL);
  
  
  
        if(av_open_input_file(&pFormatCtx, str, NULL, 0, NULL)!=0)
  
        {
  
            LOGI("Can't open file '%s'\n", str);
  
            return 1;
  
        }
  
        else
  
        {
  
            LOGI("File is opened\n");
  
            LOGI("File '%s', Codec %s",pFormatCtx->filename,pFormatCtx->iformat->name);
  
        }
  
  
  
  
  
    // Dump information about file onto standard error
  
  
  
    LOGI("dump_format");
  
    dump_format(pFormatCtx, 0, filename, 0);
  
    LOGI("dump_format DONE");
  
    // Find the first video stream
  
    videoStream=-1;
  
    for(i=0; inb_streams; i++)
  
      if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)
  
        //if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
  
        {
  
            LOGI("videoStream:: %d",videoStream);
  
        videoStream=i;
  
        break;
  
      }
  
    if(videoStream==-1)
  
      return -1; // Didn't find a video stream
  
  
  
    // Get a pointer to the codec context for the video stream
  
    pCodecCtx=pFormatCtx->streams[videoStream]->codec;
  
  
  
    // Find the decoder for the video stream
  
    pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  
    if(pCodec==NULL) {
  
      fprintf(stderr, "Unsupported codec!\n");
  
      LOGI("Unsupported codec!\n");
  
      return -1; // Codec not found
  
    }
  
    // Open codec
  
    if(avcodec_open(pCodecCtx, pCodec)<0){
  
        LOGI("Codec Opened!\n");
  
      return -1; // Could not open codec
  
    }
  
    // Allocate video frame
  
    pFrame=avcodec_alloc_frame();
  
  
  
    // Allocate an AVFrame structure
  
    pFrameRGB=avcodec_alloc_frame();
  
    if(pFrameRGB==NULL){
  
  
  
        LOGI("checking --->>> pFrameRGB==NULL\n");
  
      return -1;
  
    }
  
    // Determine required buffer size and allocate buffer
  
  
  
    LOGI("Determine required buffer size and allocate buffer\n");
  
    numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
  
                                pCodecCtx->height);
  
  
  
    LOGI("numBytes %d",numBytes);
  
  
  
    buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  
  
    // Assign appropriate parts of buffer to image planes in pFrameRGB
  
    // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  
    // of AVPicture
  
    avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
  
                   pCodecCtx->width, pCodecCtx->height);
  
  
  
    // Read frames and save first five frames to disk
  
    i=0;
  
    while(av_read_frame(pFormatCtx, &packet)>=0) {
  
      // Is this a packet from the video stream?
  
      if(packet.stream_index==videoStream) {
  
        // Decode video frame
  
          avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished,&packet);
  
                             //packet.data, packet.size);
  
  
  
        // Did we get a video frame?
  
        if(frameFinished) {
  
          // Convert the image from its native format to RGB
  
          /*Temporarily down
  
           *
  
           * img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24,
  
                      (AVPicture*)pFrame, pCodecCtx->pix_fmt, pCodecCtx->width,pCodecCtx->height);*/
  
  
  
          // Save the frame to phone memory
  
            LOGI("Saving Frame\n");
  
           SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, ++i);
  
           LOGI("After Saving Frame\n");
  
        }
  
      }
  
  
  
      // Free the packet that was allocated by av_read_frame
  
      av_free_packet(&packet);
  
    }
  
  
  
    // Free the RGB image
  
    av_free(buffer);
  
    av_free(pFrameRGB);
  
  
  
    // Free the YUV frame
  
    av_free(pFrame);
  
  
  
    // Close the codec
  
    avcodec_close(pCodecCtx);
  
  
  
    // Close the video file
  
    av_close_input_file(pFormatCtx);
  
  
  
    return 0;
  
  }

  after compiling the code i get this in log,

  07-04 10:58:38.961: D/dalvikvm(1010): Trying to load lib /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so 0x4051e878
  
  07-04 10:58:38.971: D/dalvikvm(1010): Added shared lib /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so 0x4051e878
  
  07-04 10:58:38.971: D/dalvikvm(1010): No JNI_OnLoad found in /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so 0x4051e878, skipping init
  
  07-04 10:58:39.011: I/System.out(1010): Creating Engine
  
  07-04 10:58:39.011: I/mylib(1010): initiated
  
  07-04 10:58:39.011: I/System.out(1010): Decoding Video
  
  07-04 10:58:39.011: I/System.out(1010): passing video::/sdcard/NativeMedia.ts
  
  07-04 10:58:39.101: W/dalvikvm(231): disableGcForExternalAlloc: false
  
  07-04 10:58:39.121: I/DEBUG(71): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  
  07-04 10:58:39.121: I/DEBUG(71): Build fingerprint: 'htc_asia_india/htc_icong/icong:2.3.3/GRI40/68450.5:user/release-keys'
  
  07-04 10:58:39.121: I/DEBUG(71): pid: 1010, tid: 1010  >>> ru.dzakhov.ffmpeg.test <<<
  
  07-04 10:58:39.121: I/DEBUG(71): signal 4 (SIGILL), code 1 (ILL_ILLOPC), fault addr 8102de90
  
  07-04 10:58:39.121: I/DEBUG(71):  r0 0000ac28  r1 40521b98  r2 40526340  r3 42157cc8
  
  07-04 10:58:39.121: I/DEBUG(71):  r4 bee7d368  r5 00000004  r6 40521b98  r7 42157c88
  
  07-04 10:58:39.121: I/DEBUG(71):  r8 bee7d348  r9 42157c80  10 42157c6c  fp 42f0f04c
  
  07-04 10:58:39.121: I/DEBUG(71):  ip 8102de91  sp bee7d348  lr 80018378  pc 8102de90  cpsr a0000030
  
  07-04 10:58:39.121: I/DEBUG(71):  d0  4140000041600000  d1  3ff0000041680000
  
  07-04 10:58:39.121: I/DEBUG(71):  d2  bf80000000000000  d3  0000000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  d4  0000000000000000  d5  3ff000003f800000
  
  07-04 10:58:39.121: I/DEBUG(71):  d6  bff000003f800000  d7  4160000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  d8  0000000000000000  d9  0000000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  d10 0000000000000000  d11 0000000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  d12 0000000000000000  d13 0000000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  d14 0000000000000000  d15 0000000000000000
  
  07-04 10:58:39.121: I/DEBUG(71):  scr 20000012
  
  07-04 10:58:39.221: I/DEBUG(71):          #00  pc 0002de90  /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #01  pc 0004f13c  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #02  pc 0001d584  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #03  pc 00022b8c  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #04  pc 00021a80  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #05  pc 0006060a  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #06  pc 0006828e  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #07  pc 0001d584  /system/lib/libdvm.so
  
  07-04 10:58:39.221: I/DEBUG(71):          #08  pc 00022b8c  /system/lib/libdvm.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #09  pc 00021a80  /system/lib/libdvm.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #10  pc 0006045c  /system/lib/libdvm.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #11  pc 0004c430  /system/lib/libdvm.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #12  pc 00037638  /system/lib/libandroid_runtime.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #13  pc 00038456  /system/lib/libandroid_runtime.so
  
  07-04 10:58:39.231: I/DEBUG(71):          #14  pc 00008ca2  /system/bin/app_process
  
  07-04 10:58:39.231: I/DEBUG(71):          #15  pc 00014f24  /system/lib/libc.so
  
  07-04 10:58:39.231: I/DEBUG(71): code around pc:
  
  07-04 10:58:39.231: I/DEBUG(71): 8102de70 003d9cd0 00000408 0029e598 0029e5de 
  
  07-04 10:58:39.231: I/DEBUG(71): 8102de80 0029e5d8 0029e5d8 0029e5cc 0029e5c8 
  
  07-04 10:58:39.231: I/DEBUG(71): 8102de90 4ff0e92d b0994604 f0004615 6823f945 
  
  07-04 10:58:39.231: I/DEBUG(71): 8102dea0 46294620 32a4f8d3 47982200 46044f81 
  
  07-04 10:58:39.231: I/DEBUG(71): 8102deb0 a8172300 22004621 9300447f f9c0f060 
  
  07-04 10:58:39.231: I/DEBUG(71): code around lr:
  
  07-04 10:58:39.231: I/DEBUG(71): 80018358 3497c004 3488c004 3afffff9 e2888004 
  
  07-04 10:58:39.231: I/DEBUG(71): 80018368 eafffff9 e899000c e594c008 e12fff3c 
  
  07-04 10:58:39.231: I/DEBUG(71): 80018378 e3550000 1594c00c 188c0003 e914a3f0 
  
  07-04 10:58:39.231: I/DEBUG(71): 80018388 e1a05e22 e5946004 e3a02000 e4d6c001 
  
  07-04 10:58:39.231: I/DEBUG(71): 80018398 e35c0000 0a000007 e2822001 e35c0044 
  
  07-04 10:58:39.231: I/DEBUG(71): stack:
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d308  000001b4  
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d30c  c0000000  
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d310  80018540  /system/lib/libdvm.so
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d314  0000cf98  
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d318  42157c6c  
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d31c  afd139d9  /system/lib/libc.so
  
  07-04 10:58:39.231: I/DEBUG(71):     bee7d320  0002de91  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d324  0000000e  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d328  80018540  /system/lib/libdvm.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d32c  00000070  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d330  42157c6c  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d334  00238100  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d338  00000000  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d33c  00000000  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d340  df002777  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d344  e3a070ad  
  
  07-04 10:58:39.241: I/DEBUG(71): #00 bee7d348  423692b4  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d34c  0000cf98  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d350  40521b98  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d354  8102de91  /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d358  80018540  /system/lib/libdvm.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d35c  0000cf98  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d360  bee7d368  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d364  800499df  /system/lib/libdvm.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d368  42157c80  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d36c  42d58795  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d370  8102de91  /data/data/ru.dzakhov.ffmpeg.test/lib/libmylib.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d374  bee7d418  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d378  00016de0  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d37c  0000ac28  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d380  00000001  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d384  bee7d418  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d388  42157c80  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d38c  40521b98  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d390  423692b4  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d394  800499a1  /system/lib/libdvm.so
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d398  42157c80  
  
  07-04 10:58:39.241: I/DEBUG(71):     bee7d39c  8004f13f  /system/lib/libdvm.so
  
  07-04 10:58:39.241: I/DEBUG(71): #01 bee7d3a0  00000002  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3a4  0000000e  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3a8  bee7d418  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3ac  0000cf98  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3b0  400198b8  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3b4  42d5861c  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3b8  42157c98  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3bc  bee7d410  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3c0  40521b98  
  
  07-04 10:58:39.251: I/DEBUG(71):     bee7d3c4  8001d588  /system/lib/libdvm.so

  Unable to understand what’s exact problem is there ?
  Here SaveFrame function is used it looks like,

  void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
  
    FILE *pFile;
  
    char szFilename[32];
  
    int  y;
  
  
  
    // Open file
  
    LOGI("Opening file!");
  
    sprintf(szFilename, "frame%d.ppm", iFrame);
  
  
  
    pFile=fopen(szFilename, "wb");
  
    if(pFile==NULL)
  
      return;
  
  
  
    // Write header
  
    fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
    //LOGI("width::"+width+"Height::"+height);
  
    // Write pixel data
  
    for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
    }
  
    // Close file
  
    fclose(pFile);
  
  }

  in log I didn’t get any Log which i placed in the code !

  Please help me out,

  Thanks

• cutting a video with ffmpeg with an absolute endposition

  4 février 2015, par nonsenz

  I want to use ffmpeg to slice a video into parts. I have two absolute "positions" and not a start and a duration. So i can’t use it like that :

  ffmpeg -ss 00:00:12.12 -t 00:00:14.13 -i foo.mov...

  (again, the time after -t is not a duration) Do i have to calculate the duration between the to positions or is there a way ffmpeg can do this for me ?

• How to contribute to open source, for companies

  18 octobre 2010, par Dark Shikari — development, open source, x264

  I have seen many nigh-incomprehensible attempts by companies to contribute to open source projects, including x264. Developers are often simply boggled, wondering why the companies seem incapable of proper communication. The companies assume the developers are being unreceptive, while the developers assume the companies are being incompetent, idiotic, or malicious. Most of this seems to boil down to a basic lack of understanding of how open source works, resulting in a wide variety of misunderstandings. Accordingly, this post will cover the dos and don’ts of corporate contribution to open source.

  Do : contact the project using their preferred medium of communication.

  Most open source projects use public methods of communication, such as mailing lists and IRC. It’s not the end of the world if you mistakenly make contact with the wrong people or via the wrong medium, but be prepared to switch to the correct one once informed ! You may not be experienced using whatever form of communication the project uses, but if you refuse to communicate through proper channels, they will likely not be as inclined to assist you. Larger open source projects are often much like companies in that they have different parts to their organization with different roles. Don’t assume that everyone is a major developer !

  If you don’t know what to do, a good bet is often to just ask someone.

  Don’t : contact only one person.

  Open source projects are a communal effort. Major contributions are looked over by multiple developers and are often discussed by the community as a whole. Yet many companies tend to contact only a single person in lieu of dealing with the project proper. This has many flaws : to begin with, it forces a single developer (who isn’t paid by you) to act as your liaison, adding yet another layer between what you want and the people you want to talk to. Contribution to open source projects should not be a game of telephone.

  Of course, there are exceptions to this : sometimes a single developer is in charge of the entirety of some particular aspect of a project that you intend to contribute to, in which case this might not be so bad.

  Do : make clear exactly what it is you are contributing.

  Are you contributing code ? Development resources ? Money ? API documentation ? Make it as clear as possible, from the start ! How developers react, which developers get involved, and their expectations will depend heavily on what they think you are providing. Make sure their expectations match reality. Great confusion can result when they do not.

  This also applies in the reverse — if there’s something you need from the project, such as support or assistance with development of your patch, make that explicitly clear.

  Don’t : code dump.

  Code does not have intrinsic value : it is only useful as part of a working, living project. Most projects react very negatively to large “dumps” of code without associated human resources. That is, they expect you to work with them to finalize the code until it is ready to be committed. Of course, it’s better to work with the project from the start : this avoids the situation of writing 50,000 lines of code independently and then finding that half of it needs to be rewritten. Or, worse, writing an enormous amount of code only to find it completely unnecessary.

  Of course, the reverse option — keeping such code to yourself — is often even more costly, as it forces you to maintain the code instead of the official developers.

  Do : ignore trolls.

  As mentioned above, many projects use public communication methods — which, of course, allow anyone to communicate, by nature of being public. Not everyone on a project’s IRC or mailing list is necessarily qualified to officially represent the project. It is not too uncommon for a prospective corporate contributor to be turned off by the uninviting words of someone who isn’t even involved in the project due to assuming that they were. Make sure you’re dealing with the right people before making conclusions.

  Don’t : disappear.

  If you are going to try to be involved in a project, you need to stay in contact. We’ve had all too many companies who simply disappear after the initial introduction. Some tell us that we’ll need an NDA, then never provide it or send status updates. You may know why you’re not in contact — political issues at the company, product launch crunches, a nice vacation to the Bahamas — but we don’t ! If you disappear, we will assume that you gave up.

  Above all, don’t assume that being at a large successful company makes you immune to these problems. If anything, these problems seem to be the most common at the largest companies. I didn’t name any names in this post, but practically every single one of these rules has been violated at some point by companies looking to contribute to x264. In the larger scale of open source, these problems happen constantly. Don’t fall into the same traps that many other companies have.

  If you’re an open source developer reading this post, remember it next time you see a company acting seemingly nonsensically in an attempt to contribute : it’s quite possible they just don’t know what to do. And just because they’re doing it wrong doesn’t mean that it isn’t your responsibility to try to help them do it right.