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• FFMPEG - convert video without losing resolution

  29 octobre 2015, par Srh

  I am using ffmpeg to convert mp4 video from youtube. The video is HD 1080. When I convert it to mpeg2video, the video loses its sharpness, regardless of the -s 1920x1080 parameter. How can I convert the video without losing picture sharpness ? The command I use is :

  ffmpeg -i BBB.mp4 -vcodec mpeg2video -s1920x1080 -acodec copy -f mpegts BBB.ts

• FFmpeg : generating H264 video in c++

  13 octobre 2015, par EZEROFIVE EMD

  Im using ffmpeg library in windows with vs2012 to convert a series of images into Mp4 with H264 encoding. Im new to FFMPEG.

  Below is my code. Everything went fine. Video is created.But i can play the video in vlc player only if i changed the extension to ".h264", also when i check for codec information it says "H264 - MPEG-4 AVC (part 10) (h264)". but when i checked the same for other mp4 videos which are downloaded from web. it says "H264 - MPEG-4" AVC (part 10) (avc1)". I dont understand where it went wrong. Also i searched a lot, some says like add SPS and PPS.

  const uint8_t sps[] = { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00,
  
  0x0a, 0xf8, 0x41, 0xa2 };
  
  const uint8_t pps[] = { 0x00, 0x00, 0x00, 0x01, 0x68, 0xce,
  
  0x38, 0x80 };

  So i added the above value to video file before i add the image stream. But no luck.
  Can anyone help on this..Thanks in advance.

  const uint8_t sps[] = { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00,
  
  0x0a, 0xf8, 0x41, 0xa2 };
  
  const uint8_t pps[] = { 0x00, 0x00, 0x00, 0x01, 0x68, 0xce,
  
  0x38, 0x80 };
  
  const uint8_t slice_header[] = { 0x00, 0x00, 0x00, 0x01, 0x05, 0x88,
  
  0x84, 0x21, 0xa0 };
  
  const uint8_t macroblock_header[] = { 0x0d, 0x00 };
  
  
  
  const uint8_t spspps[] = { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0x00, 0x0a, 0xf8, 0x41, 0xa2, 
  
                             0x00, 0x00, 0x00, 0x01, 0x68, 0xce, 0x38, 0x80
  
                           };
  
  
  
  int ff_load_image(uint8_t *data[4], int linesize[4],
  
          int *w, int *h, enum PixelFormat *pix_fmt,
  
          const char *filename, void *log_ctx)
  
      {
  
          AVInputFormat *iformat = NULL;
  
          AVFormatContext *format_ctx = NULL;
  
          AVCodec *codec=NULL;
  
          AVCodecContext *codec_ctx=NULL;
  
          AVFrame *frame=NULL;
  
          int frame_decoded, ret = 0;
  
          AVPacket pkt;
  
  
  
          av_register_all();
  
  
  
          iformat = av_find_input_format("image2");
  
          if ((ret = avformat_open_input(&format_ctx, filename, iformat, NULL)) < 0) {
  
              return ret;
  
          }
  
  
  
          codec_ctx = format_ctx->streams[0]->codec;
  
          codec = avcodec_find_decoder(codec_ctx->codec_id);
  
          if (!codec) {
  
              ret = AVERROR(EINVAL);
  
              goto end;
  
          }
  
  
  
          if ((ret = avcodec_open2(codec_ctx, codec, NULL)) < 0) {
  
              goto end;
  
          }
  
  
  
          //if (!(frame = avcodec_alloc_frame()) ) {
  
          if (!(frame = av_frame_alloc()) ) {
  
              ret = AVERROR(ENOMEM);
  
              goto end;
  
          }
  
  
  
          ret = av_read_frame(format_ctx, &pkt);
  
          if (ret < 0) {
  
              goto end;
  
          }
  
  
  
          ret = avcodec_decode_video2(codec_ctx, frame, &frame_decoded, &pkt);
  
          if (ret < 0 || !frame_decoded) {
  
              goto end;
  
          }
  
          ret = 0;
  
  
  
          *w       = frame->width;
  
          *h       = frame->height;
  
          *pix_fmt = (PixelFormat)frame->format;
  
  
  
          if ((ret = av_image_alloc(data, linesize, *w, *h, (AVPixelFormat)*pix_fmt, 16)) < 0)
  
              goto end;
  
          ret = 0;
  
  
  
          av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, (AVPixelFormat)*pix_fmt, *w, *h);
  
  
  
  end:
  
          if(codec_ctx) { avcodec_close(codec_ctx); }
  
          if(format_ctx) { avformat_close_input(&format_ctx); }
  
          if(frame) { av_freep(&frame); }
  
          av_free_packet(&pkt);
  
                  return ret;
  
      }
  
  
  
      int load_image_into_frame(AVFrame *frame, const char *filename)
  
      {
  
          int retval = -1, res;
  
          static struct SwsContext *sws_ctx;
  
          uint8_t *image_data[4];
  
          int linesize[4];
  
          int source_width, source_height;
  
          enum PixelFormat source_fmt;
  
  
  
          res = ff_load_image(image_data, linesize, &source_width, &source_height, &source_fmt, filename, NULL);
  
  
  
          if (source_fmt != frame->format) {
  
              sws_ctx = sws_getContext(source_width, source_height, (AVPixelFormat)source_fmt,
  
                  frame->width, frame->height, (AVPixelFormat)frame->format,
  
                  sws_flags, NULL, NULL, NULL);
  
  
  
              sws_scale(sws_ctx,
  
                  (const uint8_t * const *)image_data, linesize,
  
                  0, frame->height, frame->data, frame->linesize);
  
          }
  
  
  
          retval = 0;
  
  error:
  
          av_freep(&image_data[0]);
  
          sws_freeContext(sws_ctx);
  
          return retval;
  
      }
  
  
  
      int write_frame_to_file(FILE *file, AVFrame *frame, AVCodecContext *codec_context, AVPacket *pkt) {
  
          int res, got_output;
  
          av_init_packet(pkt);
  
          pkt->data = NULL;
  
          pkt->size = 0;
  
  
  
          /* generate synthetic video */
  
          frame->pts += 30;
  
  
  
          res = avcodec_encode_video2(codec_context, pkt, frame, &got_output);
  
  
  
          if (got_output) {
  
  
  
              fwrite(pkt->data, 1, pkt->size, file);
  
              av_free_packet(pkt);
  
          }
  
          return 0;
  
  error:
  
          return -1;
  
      }
  
  
  
      int write_image_to_file(FILE *file, const char *filename, int count, AVFrame *frame, AVCodecContext *codec_context, AVPacket *pkt) {
  
          int res, i;
  
          res = load_image_into_frame(frame, filename);
  
  
  
          for (i = 0; i < count; i++) {
  
  
  
              res = write_frame_to_file(file, frame, codec_context, pkt);
  
          }
  
  
  
          return 0;
  
  error:
  
          return -1;
  
      }
  
  
  
      int write_delayed_frames_to_file(FILE *file, AVFrame *frame, AVCodecContext *codec_context, AVPacket *pkt) {
  
          int res, got_output;
  
  
  
          for (got_output = 1; got_output;) {
  
              res = avcodec_encode_video2(codec_context, pkt, NULL, &got_output);
  
  
  
              if (got_output) {
  
                  fwrite(pkt->data, 1, pkt->size, file);
  
                  av_free_packet(pkt);
  
              }
  
          }
  
  
  
          return 0;
  
  error:
  
          return -1;
  
      }
  
  
  
      AVCodecContext *get_codec_context(int width, int height, int fps)
  
      {
  
          int res;
  
          avcodec_register_all();
  
  
  
          AVCodec *codec;
  
          AVCodecContext *codec_context = NULL;
  
  
  
          codec = avcodec_find_encoder(AV_CODEC_ID_H264);
  
  
  
          codec_context = avcodec_alloc_context3(codec);
  
  
  
          codec_context->bit_rate = 441000;
  
          codec_context->width = width;
  
          codec_context->height = height;
  
          AVRational temp_113 = {1, fps};
  
          AVRational temp_114 = {fps, 1};
  
          codec_context->time_base= temp_113;
  
          codec_context->gop_size = 10;
  
          codec_context->max_b_frames=1;
  
          codec_context->pix_fmt = AV_PIX_FMT_YUV420P;        
  
  
  
          res = avcodec_open2(codec_context, codec, NULL);
  
  
  
          return codec_context;
  
  error:
  
          return NULL;
  
      }
  
  
  
      AVFrame *get_av_frame(AVCodecContext *codec_context) {
  
          int res;
  
          AVFrame *frame;
  
  
  
          frame = av_frame_alloc();
  
          frame->height = codec_context->height;
  
          frame->width = codec_context->width;
  
          frame->format = codec_context->pix_fmt;
  
          frame->pts = 0;
  
  
  
          res = av_image_alloc(frame->data, frame->linesize, frame->width, frame->height, (AVPixelFormat)frame->format, 1);
  
  
  
          return frame;
  
  error:
  
          return NULL;
  
      }
  
  
  
      int main(int argc, char **argv)
  
      {
  
          const char *filename = "result video\\test.mp4";
  
          FILE *file=NULL;
  
          int res, retval=-1;
  
          AVCodecContext *codec_context= NULL;
  
          AVFrame *frame=NULL;
  
          AVPacket pkt;
  
          uint8_t endcode[] = { 0, 0, 1, 0xb7 };
  
  
  
          codec_context = get_codec_context(1920, 1080, 30);
  
  
  
          file = fopen(filename, "wb");
  
          //check(file != NULL, "could not open destination file %s", filename);
  
  
  
          frame = get_av_frame(codec_context);        
  
  
  
          //fwrite(sps, 1, sizeof(sps), file);
  
          //fwrite(pps, 1, sizeof(pps), file);
  
  
  
          /*codec_context->extradata = (uint8_t *)malloc(sizeof(uint8_t) * sizeof(spspps));
  
  
  
          for(unsigned int index = 0; index < sizeof(spspps); index++)
  
          {
  
              codec_context->extradata[index] = spspps[index];
  
          }
  
  
  
          codec_context->extradata_size = (int)sizeof(spspps);*/
  
  
  
          codec_context->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
  
  
          int i, frames= 51;
  
          for (i = 0; i < frames; i++) {
  
              std::stringstream ss;
  
              ss<<"\\frames\\out"<<( i + 1)<<".jpg";
  
              res = write_image_to_file(file, ss.str().c_str(), 3, frame, codec_context, &pkt);
  
          }
  
  
  
  
  
          res = write_delayed_frames_to_file(file, frame, codec_context, &pkt);
  
          fwrite(endcode, 1, sizeof(endcode), file);
  
  
  
          retval = 0;
  
  error:
  
          if (file)
  
              fclose(file);
  
          if (codec_context) {
  
              avcodec_close(codec_context);
  
              av_free(codec_context);
  
          }
  
          if (frame) {
  
              av_freep(&frame->data[0]);
  
              av_free(frame);
  
          }
  
          return retval;
  
      }
  
  }

• ffmpeg javacv audio - integrate audio into video javacv

  16 juillet 2014, par Cyril Lequeux

  I’ve looked for this issue since a while but I didn’t find out any solution...
  I want to create a video from pictures with javacv (great, it works). But now I want to put in a sync way audio into my video. I heard I had to make a byte array with the sound data and then record() according to the audiobitrate/8 = audiobyterate but i didn’t find a simple sample...I’m not the first asking this question but all the same questions are still unanswered

      IplImage Image = cvLoadImage("data/photo.jpg");
  
      FrameRecorder recorder = FFmpegFrameRecorder.createDefault("out.avi", 1920, 1080);
  
      recorder.setVideoCodec(AV_CODEC_ID_MPEG4);
  
      recorder.setFrameRate(30);
  
      recorder.setFormat("avi");
  
      recorder.start();
  
          for(int s=0; s<10; s++){
  
              for(int i=0; i<30; i++){
  
                  recorder.record(Image);
  
  //Here I want to record my music.mp3 stream
  
              }
  
          }
  
          recorder.stop();

  Please help me, I’m desesperate :p
  Ps : I’m using javacv 0.3 FFMPEG 1.06 OpenCv 2.4.3