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  • Encoding using ffmpeg library fails

    29 septembre 2012, par Erik Swansson

    I've spent some time looking at the ffmpeg library and setting things up, I'm opening a .flv file. Reading and decoding and the frames, now I'm trying to encode it to MP4 but my packets end up empty.

    My code as follows

    int main (){

       avformat_open_input(&pFC, "c://wav//test2.flv", NULL, NULL);

       po = av_find_stream_info(pFC);

       //ADD LOGIC TO FIND VIDEO STREAM
       pCodecC = pFC->streams[0]->codec;

       decoder = avcodec_find_decoder(pCodecC->codec_id);
       encoder = avcodec_find_encoder(pCodecC->codec_id);
       po = avcodec_open(pCodecC, decoder);

       pCodecE =  avcodec_alloc_context3(encoder);
       /* put sample parameters */
       pCodecE->bit_rate = 400000;
       /* resolution must be a multiple of two */
       pCodecE->width = 352;
       pCodecE->height = 288;
       /* frames per second */
       pCodecE->time_base.den = 25;
       pCodecE->time_base.num = 1;
       pCodecE->gop_size = 10; /* emit one intra frame every ten frames */
       pCodecE->max_b_frames=1;
       pCodecE->pix_fmt = PIX_FMT_YUV420P;

       if(pCodecC->codec_id == CODEC_ID_H264)
           av_opt_set(pCodecE->priv_data, "preset", "slow", 0);

       po =  avcodec_open2(pCodecE, encoder, NULL);

       AVFrame *pFrame;
       // Allocate an AVFrame structure



       // Allocate video frame
       pFrame=avcodec_alloc_frame();
       int frameFinished = 0;
       int frame = 0;
       int gotpacket = 0;

       while(av_read_frame(pFC, &packet) >= 0)
       {
           if(packet.stream_index==0) //the video stream is 0
           {
               int len = avcodec_decode_video2(pCodecC, pFrame, &frameFinished, &packet);
               if(frameFinished)
               {
                   printf("frame # %i", frame);

                   po =avcodec_encode_video2(pCodecE, &spacket, pFrame, &gotpacket);
                   if(gotpacket)
                   {
                       printf("packet recieved");
                   }
                   frame++;
               }
           }
           av_free_packet(&packet);
       }


       printf("encoding done");

       return 0;
    }

    Basically everything works up to

    po =avcodec_encode_video2(pCodecE, &spacket, pFrame, &gotpacket);

    Where &gotpacket returns 0, as in an empty frame.

    Not sure what I'm doing wrong.

  • How to encode using the FFMpeg in Android (using H263)

    3 juillet 2012, par Kenny910

    I am trying to follow the sample code on encoding in the ffmpeg document and successfully build a application to encode and generate a mp4 file but I face the following problems :

    1) I am using the H263 for encoding but I can only set the width and height of the AVCodecContext to 176x144, for other case (like 720x480 or 640x480) it will return fail.

    2) I can't play the output mp4 file by using the default Android player, isn't it support H263 mp4 file ? p.s. I can play it by using other player

    3) Is there any sample code on encoding other video frame to make a new video (which mean decode the video and encode it back in different quality setting, also i would like to modify the frame content) ?

    Here is my code, thanks !

    JNIEXPORT jint JNICALL Java_com_ffmpeg_encoder_FFEncoder_nativeEncoder(JNIEnv* env, jobject thiz, jstring filename){

    LOGI("nativeEncoder()");

    avcodec_register_all();
    avcodec_init();
    av_register_all();

    AVCodec         *codec;
    AVCodecContext  *codecCtx;
    int             i;
    int             out_size;
    int             size;
    int             x;
    int             y;
    int             output_buffer_size;
    FILE            *file;
    AVFrame         *picture;
    uint8_t         *output_buffer;
    uint8_t         *picture_buffer;

    /* Manual Variables */
    int             l;
    int             fps = 30;
    int             videoLength = 5;

    /* find the H263 video encoder */
    codec = avcodec_find_encoder(CODEC_ID_H263);
    if (!codec) {
       LOGI("avcodec_find_encoder() run fail.");
    }

    codecCtx = avcodec_alloc_context();
    picture = avcodec_alloc_frame();

    /* put sample parameters */
    codecCtx->bit_rate = 400000;
    /* resolution must be a multiple of two */
    codecCtx->width = 176;
    codecCtx->height = 144;
    /* frames per second */
    codecCtx->time_base = (AVRational){1,fps};
    codecCtx->pix_fmt = PIX_FMT_YUV420P;
    codecCtx->codec_id = CODEC_ID_H263;
    codecCtx->codec_type = AVMEDIA_TYPE_VIDEO;

    /* open it */
    if (avcodec_open(codecCtx, codec) < 0) {
       LOGI("avcodec_open() run fail.");
    }

    const char* mfileName = (*env)->GetStringUTFChars(env, filename, 0);

    file = fopen(mfileName, "wb");
    if (!file) {
       LOGI("fopen() run fail.");
    }

    (*env)->ReleaseStringUTFChars(env, filename, mfileName);

    /* alloc image and output buffer */
    output_buffer_size = 100000;
    output_buffer = malloc(output_buffer_size);

    size = codecCtx->width * codecCtx->height;
    picture_buffer = malloc((size * 3) / 2); /* size for YUV 420 */

    picture->data[0] = picture_buffer;
    picture->data[1] = picture->data[0] + size;
    picture->data[2] = picture->data[1] + size / 4;
    picture->linesize[0] = codecCtx->width;
    picture->linesize[1] = codecCtx->width / 2;
    picture->linesize[2] = codecCtx->width / 2;

    for(l=0;l/encode 1 second of video
       for(i=0;i/prepare a dummy image YCbCr
           //Y
           for(y=0;yheight;y++) {
               for(x=0;xwidth;x++) {
                   picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
               }
           }

           //Cb and Cr
           for(y=0;yheight/2;y++) {
               for(x=0;xwidth/2;x++) {
                   picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
                   picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
               }
           }

           //encode the image
           out_size = avcodec_encode_video(codecCtx, output_buffer, output_buffer_size, picture);
           fwrite(output_buffer, 1, out_size, file);
       }

       //get the delayed frames
       for(; out_size; i++) {
           out_size = avcodec_encode_video(codecCtx, output_buffer, output_buffer_size, NULL);
           fwrite(output_buffer, 1, out_size, file);
       }
    }

    //add sequence end code to have a real mpeg file
    output_buffer[0] = 0x00;
    output_buffer[1] = 0x00;
    output_buffer[2] = 0x01;
    output_buffer[3] = 0xb7;

    fwrite(output_buffer, 1, 4, file);
    fclose(file);
    free(picture_buffer);
    free(output_buffer);
    avcodec_close(codecCtx);
    av_free(codecCtx);
    av_free(picture);

    LOGI("finish");

    return 0; }
  • iPhone camera shooting video using the AVCaptureSession and using ffmpeg CMSampleBufferRef a change in h.264 format is the issue. please advice

    4 janvier 2012, par isaiah

    My goal is h.264/AAC , mpeg2-ts streaming to server from iphone device.

    Current my source is FFmpeg+libx264 compile success. I Know gnu License. I want the demo program.

    I'm want to know that

    1.CMSampleBufferRef to AVPicture data is success ?

    avpicture_fill((AVPicture*)pFrame, rawPixelBase, PIX_FMT_RGB32, width, height);
     pFrame linesize and data is not null but pst -9233123123 . outpic also .
    Because of this I have to guess 'non-strictly-monotonic PTS' message

    2.This log is repeat.

    encoding frame (size= 0)
    encoding frame = "" , 'avcodec_encode_video' return 0 is success but always 0 .

    I don't know what to do...

    2011-06-01 15:15:14.199 AVCam[1993:7303] pFrame = avcodec_alloc_frame();
    2011-06-01 15:15:14.207 AVCam[1993:7303] avpicture_fill = 1228800
    Video encoding
    2011-0601 15:5:14.215 AVCam[1993:7303] codec = 5841844
    [libx264 @ 0x1441e00] using cpu capabilities: ARMv6 NEON
    [libx264 @ 0x1441e00] profile Constrained Baseline, level 2.0[libx264 @ 0x1441e00] non-strictly-monotonic PTS
    encoding frame (size=    0)
    encoding frame
    [libx264 @ 0x1441e00] final ratefactor: 26.74

    3.I have to guess 'non-strictly-monotonic PTS' message is the cause of all problems.
    what is this 'non-strictly-monotonic PTS' .

     this is source 

    (void)        captureOutput:(AVCaptureOutput *)captureOutput
           didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
                  fromConnection:(AVCaptureConnection *)connection
    {

       if( !CMSampleBufferDataIsReady(sampleBuffer) )
       {
           NSLog( @"sample buffer is not ready. Skipping sample" );
           return;
       }


       if( [isRecordingNow isEqualToString:@"YES"] )
       {
           lastSampleTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
           if( videoWriter.status != AVAssetWriterStatusWriting  )
           {
               [videoWriter startWriting];
               [videoWriter startSessionAtSourceTime:lastSampleTime];
           }

           if( captureOutput == videooutput )
           {
               [self newVideoSample:sampleBuffer];

               CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
               CVPixelBufferLockBaseAddress(pixelBuffer, 0);

               // access the data
               int width = CVPixelBufferGetWidth(pixelBuffer);
               int height = CVPixelBufferGetHeight(pixelBuffer);
               unsigned char *rawPixelBase = (unsigned char *)CVPixelBufferGetBaseAddress(pixelBuffer);

               AVFrame *pFrame;
               pFrame = avcodec_alloc_frame();
               pFrame->quality = 0;

               NSLog(@"pFrame = avcodec_alloc_frame(); ");

    //          int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);

    //          int bytesSize = height * bytesPerRow ;  

    //          unsigned char *pixel = (unsigned char*)malloc(bytesSize);

    //          unsigned char *rowBase = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);

    //          memcpy (pixel, rowBase, bytesSize);


               int avpicture_fillNum = avpicture_fill((AVPicture*)pFrame, rawPixelBase, PIX_FMT_RGB32, width, height);//PIX_FMT_RGB32//PIX_FMT_RGB8
               //NSLog(@"rawPixelBase = %i , rawPixelBase -s = %s",rawPixelBase, rawPixelBase);
               NSLog(@"avpicture_fill = %i",avpicture_fillNum);
               //NSLog(@"width = %i,height = %i",width, height);



               // Do something with the raw pixels here

               CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

               //avcodec_init();
               //avdevice_register_all();
               av_register_all();





               AVCodec *codec;
               AVCodecContext *c= NULL;
               int  out_size, size, outbuf_size;
               //FILE *f;
               uint8_t *outbuf;

               printf("Video encoding\n");

               /* find the mpeg video encoder */
               codec =avcodec_find_encoder(CODEC_ID_H264);//avcodec_find_encoder_by_name("libx264"); //avcodec_find_encoder(CODEC_ID_H264);//CODEC_ID_H264);
               NSLog(@"codec = %i",codec);
               if (!codec) {
                   fprintf(stderr, "codec not found\n");
                   exit(1);
               }

               c= avcodec_alloc_context();

               /* put sample parameters */
               c->bit_rate = 400000;
               c->bit_rate_tolerance = 10;
               c->me_method = 2;
               /* resolution must be a multiple of two */
               c->width = 352;//width;//352;
               c->height = 288;//height;//288;
               /* frames per second */
               c->time_base= (AVRational){1,25};
               c->gop_size = 10;//25; /* emit one intra frame every ten frames */
               //c->max_b_frames=1;
               c->pix_fmt = PIX_FMT_YUV420P;

               c ->me_range = 16;
               c ->max_qdiff = 4;
               c ->qmin = 10;
               c ->qmax = 51;
               c ->qcompress = 0.6f;

               /* open it */
               if (avcodec_open(c, codec) < 0) {
                   fprintf(stderr, "could not open codec\n");
                   exit(1);
               }


               /* alloc image and output buffer */
               outbuf_size = 100000;
               outbuf = malloc(outbuf_size);
               size = c->width * c->height;

               AVFrame* outpic = avcodec_alloc_frame();
               int nbytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);

               //create buffer for the output image
               uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes);

    #pragma mark -  

               fflush(stdout);

    <pre>//         int numBytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);
    //          uint8_t *buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
    //          
    //          //UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"10%d", i]];
    //          CGImageRef newCgImage = [self imageFromSampleBuffer:sampleBuffer];//[image CGImage];
    //          
    //          CGDataProviderRef dataProvider = CGImageGetDataProvider(newCgImage);
    //          CFDataRef bitmapData = CGDataProviderCopyData(dataProvider);
    //          buffer = (uint8_t *)CFDataGetBytePtr(bitmapData);  
    //          
    //          avpicture_fill((AVPicture*)pFrame, buffer, PIX_FMT_RGB8, c->width, c->height);
               avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, c->width, c->height);

               struct SwsContext* fooContext = sws_getContext(c->width, c->height,
                                                              PIX_FMT_RGB8,
                                                              c->width, c->height,
                                                              PIX_FMT_YUV420P,
                                                              SWS_FAST_BILINEAR, NULL, NULL, NULL);

               //perform the conversion
               sws_scale(fooContext, pFrame->data, pFrame->linesize, 0, c->height, outpic->data, outpic->linesize);
               // Here is where I try to convert to YUV

               /* encode the image */

               out_size = avcodec_encode_video(c, outbuf, outbuf_size, outpic);
               printf("encoding frame (size=%5d)\n", out_size);
               printf("encoding frame %s\n", outbuf);


               //fwrite(outbuf, 1, out_size, f);

               //              free(buffer);
               //              buffer = NULL;      



               /* add sequence end code to have a real mpeg file */
    //          outbuf[0] = 0x00;
    //          outbuf[1] = 0x00;
    //          outbuf[2] = 0x01;
    //          outbuf[3] = 0xb7;
               //fwrite(outbuf, 1, 4, f);
               //fclose(f);
               free(outbuf);

               avcodec_close(c);
               av_free(c);
               av_free(pFrame);
               printf("\n");
    </pre>