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• Anomalie #3223 : Liste des mot-clés liés à un objet : boutons d’actions affichés quelles que soien...

  18 juillet 2014, par marcimat ☺☮☯♫

  … commentaire non destiné à ce ticket ! …

• How to play raw h264 produced by MediaCodec encoder ?

  1er novembre 2014, par jackos2500

  I’m a bit new when it comes to MediaCodec (and video encoding/decoding in general), so correct me if anything I say here is wrong.

  I want to play the raw h264 output of MediaCodec with VLC/ffplay. I need this to play becuase my end goal is to stream some live video to a computer, and MediaMuxer only produces a file on disk rather than something I can stream with (very) low latency to a desktop. (I’m open to other solutions, but I have not found anything else that fits the latency requirement)

  Here is the code I’m using encode the video and write it to a file : (it’s based off the MediaCodec example found here, only with the MediaMuxer part removed)

  package com.jackos2500.droidtop;
  
  
  
  import android.media.MediaCodec;
  
  import android.media.MediaCodecInfo;
  
  import android.media.MediaFormat;
  
  import android.opengl.EGL14;
  
  import android.opengl.EGLConfig;
  
  import android.opengl.EGLContext;
  
  import android.opengl.EGLDisplay;
  
  import android.opengl.EGLExt;
  
  import android.opengl.EGLSurface;
  
  import android.opengl.GLES20;
  
  import android.os.Environment;
  
  import android.util.Log;
  
  import android.view.Surface;
  
  
  
  import java.io.BufferedOutputStream;
  
  import java.io.File;
  
  import java.io.FileOutputStream;
  
  import java.io.IOException;
  
  import java.nio.ByteBuffer;
  
  
  
  public class StreamH264 {
  
      private static final String TAG = "StreamH264";
  
      private static final boolean VERBOSE = true;           // lots of logging
  
  
  
      // where to put the output file (note: /sdcard requires WRITE_EXTERNAL_STORAGE permission)
  
      private static final File OUTPUT_DIR = Environment.getExternalStorageDirectory();
  
  
  
      public static int MEGABIT = 1000 * 1000;
  
      private static final int IFRAME_INTERVAL = 10;
  
  
  
      private static final int TEST_R0 = 0;
  
      private static final int TEST_G0 = 136;
  
      private static final int TEST_B0 = 0;
  
      private static final int TEST_R1 = 236;
  
      private static final int TEST_G1 = 50;
  
      private static final int TEST_B1 = 186;
  
  
  
      private MediaCodec codec;
  
      private CodecInputSurface inputSurface;
  
      private BufferedOutputStream out;
  
  
  
      private MediaCodec.BufferInfo bufferInfo;
  
      public StreamH264() {
  
  
  
      }
  
  
  
      private void prepareEncoder() throws IOException {
  
          bufferInfo = new MediaCodec.BufferInfo();
  
  
  
          MediaFormat format = MediaFormat.createVideoFormat("video/avc", 1280, 720);
  
          format.setInteger(MediaFormat.KEY_BIT_RATE, 2 * MEGABIT);
  
          format.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
  
          format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
  
          format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL);
  
  
  
          codec = MediaCodec.createEncoderByType("video/avc");
  
          codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
  
          inputSurface = new CodecInputSurface(codec.createInputSurface());
  
          codec.start();
  
  
  
          File dst = new File(OUTPUT_DIR, "test.264");
  
          out = new BufferedOutputStream(new FileOutputStream(dst));
  
      }
  
      private void releaseEncoder() throws IOException {
  
          if (VERBOSE) Log.d(TAG, "releasing encoder objects");
  
          if (codec != null) {
  
              codec.stop();
  
              codec.release();
  
              codec = null;
  
          }
  
          if (inputSurface != null) {
  
              inputSurface.release();
  
              inputSurface = null;
  
          }
  
          if (out != null) {
  
              out.flush();
  
              out.close();
  
              out = null;
  
          }
  
      }
  
      public void stream() throws IOException {
  
          try {
  
              prepareEncoder();
  
              inputSurface.makeCurrent();
  
              for (int i = 0; i < (30 * 5); i++) {
  
                  // Feed any pending encoder output into the file.
  
                  drainEncoder(false);
  
  
  
                  // Generate a new frame of input.
  
                  generateSurfaceFrame(i);
  
                  inputSurface.setPresentationTime(computePresentationTimeNsec(i, 30));
  
  
  
                  // Submit it to the encoder.  The eglSwapBuffers call will block if the input
  
                  // is full, which would be bad if it stayed full until we dequeued an output
  
                  // buffer (which we can't do, since we're stuck here).  So long as we fully drain
  
                  // the encoder before supplying additional input, the system guarantees that we
  
                  // can supply another frame without blocking.
  
                  if (VERBOSE) Log.d(TAG, "sending frame " + i + " to encoder");
  
                  inputSurface.swapBuffers();
  
              }
  
              // send end-of-stream to encoder, and drain remaining output
  
              drainEncoder(true);
  
          } finally {
  
              // release encoder, muxer, and input Surface
  
              releaseEncoder();
  
          }
  
      }
  
  
  
      private void drainEncoder(boolean endOfStream) throws IOException {
  
          final int TIMEOUT_USEC = 10000;
  
          if (VERBOSE) Log.d(TAG, "drainEncoder(" + endOfStream + ")");
  
  
  
          if (endOfStream) {
  
              if (VERBOSE) Log.d(TAG, "sending EOS to encoder");
  
              codec.signalEndOfInputStream();
  
          }
  
          ByteBuffer[] outputBuffers = codec.getOutputBuffers();
  
          while (true) {
  
              int encoderStatus = codec.dequeueOutputBuffer(bufferInfo, TIMEOUT_USEC);
  
              if (encoderStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
  
                  // no output available yet
  
                  if (!endOfStream) {
  
                      break;      // out of while
  
                  } else {
  
                      if (VERBOSE) Log.d(TAG, "no output available, spinning to await EOS");
  
                  }
  
              } else if (encoderStatus == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
  
                  // not expected for an encoder
  
                  outputBuffers = codec.getOutputBuffers();
  
              } else if (encoderStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
  
                  // should happen before receiving buffers, and should only happen once
  
                  MediaFormat newFormat = codec.getOutputFormat();
  
                  Log.d(TAG, "encoder output format changed: " + newFormat);
  
              } else if (encoderStatus < 0) {
  
                  Log.w(TAG, "unexpected result from encoder.dequeueOutputBuffer: " + encoderStatus);
  
                  // let's ignore it
  
              } else {
  
                  ByteBuffer encodedData = outputBuffers[encoderStatus];
  
                  if (encodedData == null) {
  
                      throw new RuntimeException("encoderOutputBuffer " + encoderStatus + " was null");
  
                  }
  
  
  
                  if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
  
                      // The codec config data was pulled out and fed to the muxer when we got
  
                      // the INFO_OUTPUT_FORMAT_CHANGED status.  Ignore it.
  
                      if (VERBOSE) Log.d(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG");
  
                      bufferInfo.size = 0;
  
                  }
  
  
  
                  if (bufferInfo.size != 0) {
  
                      // adjust the ByteBuffer values to match BufferInfo (not needed?)
  
                      encodedData.position(bufferInfo.offset);
  
                      encodedData.limit(bufferInfo.offset + bufferInfo.size);
  
  
  
                      byte[] data = new byte[bufferInfo.size];
  
                      encodedData.get(data);
  
                      out.write(data);
  
                      if (VERBOSE) Log.d(TAG, "sent " + bufferInfo.size + " bytes to file");
  
                  }
  
  
  
                  codec.releaseOutputBuffer(encoderStatus, false);
  
  
  
                  if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
  
                      if (!endOfStream) {
  
                          Log.w(TAG, "reached end of stream unexpectedly");
  
                      } else {
  
                          if (VERBOSE) Log.d(TAG, "end of stream reached");
  
                      }
  
                      break;      // out of while
  
                  }
  
              }
  
          }
  
      }
  
      private void generateSurfaceFrame(int frameIndex) {
  
          frameIndex %= 8;
  
  
  
          int startX, startY;
  
          if (frameIndex < 4) {
  
              // (0,0) is bottom-left in GL
  
              startX = frameIndex * (1280 / 4);
  
              startY = 720 / 2;
  
          } else {
  
              startX = (7 - frameIndex) * (1280 / 4);
  
              startY = 0;
  
          }
  
  
  
          GLES20.glClearColor(TEST_R0 / 255.0f, TEST_G0 / 255.0f, TEST_B0 / 255.0f, 1.0f);
  
          GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
  
  
  
          GLES20.glEnable(GLES20.GL_SCISSOR_TEST);
  
          GLES20.glScissor(startX, startY, 1280 / 4, 720 / 2);
  
          GLES20.glClearColor(TEST_R1 / 255.0f, TEST_G1 / 255.0f, TEST_B1 / 255.0f, 1.0f);
  
          GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
  
          GLES20.glDisable(GLES20.GL_SCISSOR_TEST);
  
      }
  
      private static long computePresentationTimeNsec(int frameIndex, int frameRate) {
  
          final long ONE_BILLION = 1000000000;
  
          return frameIndex * ONE_BILLION / frameRate;
  
      }
  
  
  
      /**
  
       * Holds state associated with a Surface used for MediaCodec encoder input.
  
       * <p>
  
       * The constructor takes a Surface obtained from MediaCodec.createInputSurface(), and uses that
  
       * to create an EGL window surface.  Calls to eglSwapBuffers() cause a frame of data to be sent
  
       * to the video encoder.
  
       * </p><p>
  
       * This object owns the Surface -- releasing this will release the Surface too.
  
       */
  
      private static class CodecInputSurface {
  
          private static final int EGL_RECORDABLE_ANDROID = 0x3142;
  
  
  
          private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
  
          private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
  
          private EGLSurface mEGLSurface = EGL14.EGL_NO_SURFACE;
  
  
  
          private Surface mSurface;
  
  
  
          /**
  
           * Creates a CodecInputSurface from a Surface.
  
           */
  
          public CodecInputSurface(Surface surface) {
  
              if (surface == null) {
  
                  throw new NullPointerException();
  
              }
  
              mSurface = surface;
  
  
  
              eglSetup();
  
          }
  
  
  
          /**
  
           * Prepares EGL.  We want a GLES 2.0 context and a surface that supports recording.
  
           */
  
          private void eglSetup() {
  
              mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
  
              if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
  
                  throw new RuntimeException("unable to get EGL14 display");
  
              }
  
              int[] version = new int[2];
  
              if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
  
                  throw new RuntimeException("unable to initialize EGL14");
  
              }
  
  
  
              // Configure EGL for recording and OpenGL ES 2.0.
  
              int[] attribList = {
  
                      EGL14.EGL_RED_SIZE, 8,
  
                      EGL14.EGL_GREEN_SIZE, 8,
  
                      EGL14.EGL_BLUE_SIZE, 8,
  
                      EGL14.EGL_ALPHA_SIZE, 8,
  
                      EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
  
                      EGL_RECORDABLE_ANDROID, 1,
  
                      EGL14.EGL_NONE
  
              };
  
              EGLConfig[] configs = new EGLConfig[1];
  
              int[] numConfigs = new int[1];
  
              EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
  
                      numConfigs, 0);
  
              checkEglError("eglCreateContext RGB888+recordable ES2");
  
  
  
              // Configure context for OpenGL ES 2.0.
  
              int[] attrib_list = {
  
                      EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
  
                      EGL14.EGL_NONE
  
              };
  
              mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
  
                      attrib_list, 0);
  
              checkEglError("eglCreateContext");
  
  
  
              // Create a window surface, and attach it to the Surface we received.
  
              int[] surfaceAttribs = {
  
                      EGL14.EGL_NONE
  
              };
  
              mEGLSurface = EGL14.eglCreateWindowSurface(mEGLDisplay, configs[0], mSurface,
  
                      surfaceAttribs, 0);
  
              checkEglError("eglCreateWindowSurface");
  
          }
  
  
  
          /**
  
           * Discards all resources held by this class, notably the EGL context.  Also releases the
  
           * Surface that was passed to our constructor.
  
           */
  
          public void release() {
  
              if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
  
                  EGL14.eglMakeCurrent(mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
  
                          EGL14.EGL_NO_CONTEXT);
  
                  EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
  
                  EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
  
                  EGL14.eglReleaseThread();
  
                  EGL14.eglTerminate(mEGLDisplay);
  
              }
  
  
  
              mSurface.release();
  
  
  
              mEGLDisplay = EGL14.EGL_NO_DISPLAY;
  
              mEGLContext = EGL14.EGL_NO_CONTEXT;
  
              mEGLSurface = EGL14.EGL_NO_SURFACE;
  
  
  
              mSurface = null;
  
          }
  
  
  
          /**
  
           * Makes our EGL context and surface current.
  
           */
  
          public void makeCurrent() {
  
              EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext);
  
              checkEglError("eglMakeCurrent");
  
          }
  
  
  
          /**
  
           * Calls eglSwapBuffers.  Use this to "publish" the current frame.
  
           */
  
          public boolean swapBuffers() {
  
              boolean result = EGL14.eglSwapBuffers(mEGLDisplay, mEGLSurface);
  
              checkEglError("eglSwapBuffers");
  
              return result;
  
          }
  
  
  
          /**
  
           * Sends the presentation time stamp to EGL.  Time is expressed in nanoseconds.
  
           */
  
          public void setPresentationTime(long nsecs) {
  
              EGLExt.eglPresentationTimeANDROID(mEGLDisplay, mEGLSurface, nsecs);
  
              checkEglError("eglPresentationTimeANDROID");
  
          }
  
  
  
          /**
  
           * Checks for EGL errors.  Throws an exception if one is found.
  
           */
  
          private void checkEglError(String msg) {
  
              int error;
  
              if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
  
                  throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
  
              }
  
          }
  
      }
  
  }
  
  </p>

  However, the file produced from this code does not play with VLC or ffplay. Can anyone tell me what I’m doing wrong ? I believe it is due to an incorrect format (or total lack) of headers required for the playing of raw h264, as I have had success playing .264 files downloaded from the internet with ffplay. Also, I’m not sure exactly how I’m going to stream this video to a computer, so if somebody could give me some suggestions as to how I might do that, I would be very grateful ! Thanks !

• How to write NALs produced by x264_encoder_encode() using ffmpeg av_interleaved_write_frame()

  21 janvier 2013, par Haleeq Usman

  I have been trying to produce a "flv" video file in the following sequence :

  av_register_all();
  
  
  
  // Open video file
  
  if (avformat_open_input(&pFormatCtx, "6.mp4", NULL, NULL) != 0)
  
      return -1; // Couldn't open file
  
  
  
  // Retrieve stream information
  
  if (avformat_find_stream_info(pFormatCtx, NULL) < 0)
  
      return -1; // Couldn't find stream information
  
  
  
  // Dump information about file onto standard error
  
  av_dump_format(pFormatCtx, 0, "input_file.mp4", 0);
  
  
  
  // Find the first video stream
  
  videoStream = -1;
  
  for (i = 0; i < pFormatCtx->nb_streams; i++)
  
      if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  
          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");
  
      return -1; // Codec not found
  
  }
  
  // Open codec
  
  if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0)
  
      return -1; // Could not open codec
  
  
  
  // Allocate video frame
  
  pFrame = avcodec_alloc_frame();
  
  
  
  // Allocate video frame
  
  pFrame = avcodec_alloc_frame();
  
  
  
  // Allocate an AVFrame structure
  
  pFrameYUV420 = avcodec_alloc_frame();
  
  if (pFrameYUV420 == NULL)
  
      return -1;
  
  
  
  // Determine required buffer size and allocate buffer
  
  numBytes = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
  
  buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
  
  
  
  // Assign appropriate parts of buffer to image planes in pFrameYUV420
  
  // Note that pFrameYUV420 is an AVFrame, but AVFrame is a superset of AVPicture
  
  avpicture_fill((AVPicture *) pFrameRGB, buffer, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
  
  
  
  // Setup scaler
  
  img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, SWS_BILINEAR, 0, 0, 0);
  
  if (img_convert_ctx == NULL) {
  
      fprintf(stderr, "Cannot initialize the conversion context!\n");
  
      exit(1);
  
  }
  
  
  
  // Setup encoder/muxing now
  
  filename = "output_file.flv";
  
  fmt = av_guess_format("flv", filename, NULL);
  
  if (fmt == NULL) {
  
      printf("Could not guess format.\n");
  
      return -1;
  
  }
  
  /* allocate the output media context */
  
  oc = avformat_alloc_context();
  
  if (oc == NULL) {
  
      printf("could not allocate context.\n");
  
      return -1;
  
  }
  
  oc->oformat = fmt;
  
  snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
  
  
  
  video_st = NULL;
  
  if (fmt->video_codec != AV_CODEC_ID_NONE) {
  
      video_st = add_stream(oc, &video_codec, fmt->video_codec);
  
  }
  
  
  
  // Let's see some information about our format
  
  av_dump_format(oc, 0, filename, 1);
  
  
  
  /* open the output file, if needed */
  
  if (!(fmt->flags & AVFMT_NOFILE)) {
  
      ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
  
      if (ret < 0) {
  
          fprintf(stderr, "Could not open '%s': %s\n", filename, av_err2str(ret));
  
          return 1;
  
      }
  
      }
  
  /* Write the stream header, if any. */
  
  ret = avformat_write_header(oc, NULL);
  
  if (ret < 0) {
  
      fprintf(stderr, "Error occurred when opening output file: %s\n", av_err2str(ret));
  
      return 1;
  
  }
  
  
  
  // Setup x264 params
  
  x264_param_t param;
  
  x264_param_default_preset(&param, "veryfast", "zerolatency");
  
  param.i_threads = 1;
  
  param.i_width = video_st->codec->width;
  
  param.i_height = video_st->codec->height;
  
  param.i_fps_num = STREAM_FRAME_RATE; // 30 fps, same as video
  
  param.i_fps_den = 1;
  
  // Intra refres:
  
  param.i_keyint_max = STREAM_FRAME_RATE;
  
  param.b_intra_refresh = 1;
  
  // Rate control:
  
  param.rc.i_rc_method = X264_RC_CRF;
  
  param.rc.f_rf_constant = 25;
  
  param.rc.f_rf_constant_max = 35;
  
  // For streaming:
  
  param.b_repeat_headers = 1;
  
  param.b_annexb = 1;
  
  x264_param_apply_profile(&param, "baseline");
  
  
  
  x264_t* encoder = x264_encoder_open(&param);
  
  x264_picture_t pic_in, pic_out;
  
  x264_picture_alloc(&pic_in, X264_CSP_I420, video_st->codec->width, video_st->codec->height);
  
  
  
  x264_nal_t* nals;
  
  int i_nals;
  
  
  
  // The loop:
  
  // 1. Read frames
  
  // 2. Decode the frame
  
  // 3. Attempt to re-encode using x264
  
  // 4. Write the x264 encoded frame using av_interleaved_write_frame
  
  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);
  
  
  
          // Did we get a video frame?
  
          if (frameFinished) {
  
              sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pic_in.img.plane, pic_in.img.i_stride);
  
              int frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out);
  
  
  
              if (frame_size >= 0) {
  
                  if (i_nals < 0)
  
                      printf("invalid frame size: %d\n", i_nals);
  
                  // write out NALs
  
                  for (i = 0; i < i_nals; i++) {
  
                      // initalize a packet
  
                      AVPacket p;
  
                      av_init_packet(&p);
  
                      p.data = nals[i].p_payload;
  
                      p.size = nals[i].i_payload;
  
                      p.stream_index = video_st->index;
  
                      p.flags = AV_PKT_FLAG_KEY;
  
                      p.pts = AV_NOPTS_VALUE;
  
                      p.dts = AV_NOPTS_VALUE;
  
                      ret = av_interleaved_write_frame(oc, &p);
  
                  }
  
              }
  
              printf("encoded frame #%d\n", frame_count);
  
              frame_count++;
  
          }
  
      }
  
  
  
      // Free the packet that was allocated by av_read_frame
  
      av_free_packet(&packet);
  
  }
  
  
  
  // Now we free up resources used/close codecs, and finally close our program.

  Here is the implementation for the add_stream() function :

  /* Add an output stream. */
  
  static AVStream *add_stream(AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id) {
  
      AVCodecContext *c;
  
      AVStream *st;
  
      int r;
  
      /* find the encoder */
  
      *codec = avcodec_find_encoder(codec_id);
  
      if (!(*codec)) {
  
          fprintf(stderr, "Could not find encoder for '%s'\n",
  
                  avcodec_get_name(codec_id));
  
          exit(1);
  
      }
  
      st = avformat_new_stream(oc, *codec);
  
      if (!st) {
  
          fprintf(stderr, "Could not allocate stream\n");
  
          exit(1);
  
      }
  
      st->id = oc->nb_streams - 1;
  
      c = st->codec;
  
      switch ((*codec)->type) {
  
      case AVMEDIA_TYPE_AUDIO:
  
          st->id = 1;
  
          c->sample_fmt = AV_SAMPLE_FMT_FLTP;
  
          c->bit_rate = 64000;
  
          c->sample_rate = 44100;
  
          c->channels = 2;
  
          break;
  
      case AVMEDIA_TYPE_VIDEO:
  
          avcodec_get_context_defaults3(c, *codec);
  
          c->codec_id = codec_id;
  
          c->bit_rate = 500*1000;
  
          //c->rc_min_rate = 500*1000;
  
          //c->rc_max_rate = 500*1000;
  
          //c->rc_buffer_size = 500*1000;
  
          /* Resolution must be a multiple of two. */
  
          c->width = 1280;
  
          c->height = 720;
  
          /* timebase: This is the fundamental unit of time (in seconds) in terms
  
           * of which frame timestamps are represented. For fixed-fps content,
  
           * timebase should be 1/framerate and timestamp increments should be
  
           * identical to 1. */
  
          c->time_base.den = STREAM_FRAME_RATE;
  
          c->time_base.num = 1;
  
          c->gop_size = 12; /* emit one intra frame every twelve frames at most */
  
          c->pix_fmt = STREAM_PIX_FMT;
  
          if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
  
              /* just for testing, we also add B frames */
  
              c->max_b_frames = 2;
  
          }
  
          if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
  
              /* Needed to avoid using macroblocks in which some coeffs overflow.
  
               * This does not happen with normal video, it just happens here as
  
               * the motion of the chroma plane does not match the luma plane. */
  
              c->mb_decision = 2;
  
          }
  
          break;
  
      default:
  
          break;
  
      }
  
      /* Some formats want stream headers to be separate. */
  
      if (oc->oformat->flags & AVFMT_GLOBALHEADER)
  
          c->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
      return st;
  
  }

  After the encoding is complete, I check the output file output_file.flv. I notice it's size is very large : 101MB and it does not play. If I use ffmpeg to decode/encode the input file, then I get an output file about 83MB in size (which is about the same size as the original .mp4 file used as input). Also, the 83MB output from just using ffmpeg C api, as opposed to using x264 for the encoding step, plays just fine. Does anyone know where I am going wrong ? I have tried researching this for a few days now but with no luck :(. I feel that I am close to making it work, however, I just cannot figure out what I am doing wrong. Thank you !