Change segment width dynamically in MediaRecorder

media/muxers/webm_muxer.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/muxers/webm_muxer.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 122 matching lines @@
 }
 
 bool WebmMuxer::OnEncodedVideo(const VideoParameters& params,
                                std::unique_ptr<std::string> encoded_data,
                                std::unique_ptr<std::string> encoded_alpha,
                                base::TimeTicks timestamp,
                                bool is_key_frame) {
   DVLOG(1) << __func__ << " - " << encoded_data->size() << "B";
   DCHECK(thread_checker_.CalledOnValidThread());
 
+  if (!last_frame_size_.IsEmpty() &&
+      last_frame_size_ != params.visible_rect_size) {
+    mkvmuxer::VideoTrack* const video_track =
+        reinterpret_cast<mkvmuxer::VideoTrack*>(
+            segment_.GetTrackByNumber(video_track_index_));
+    DCHECK(video_track);
+    video_track->set_width(params.visible_rect_size.width());
+    video_track->set_height(params.visible_rect_size.height());
+  }
+  last_frame_size_ = params.visible_rect_size;
+
   if (!video_track_index_) {
     // |track_index_|, cannot be zero (!), initialize WebmMuxer in that case.
     // http://www.matroska.org/technical/specs/index.html#Tracks
     AddVideoTrack(params.visible_rect_size, GetFrameRate(params));
     if (first_frame_timestamp_video_.is_null())
       first_frame_timestamp_video_ = timestamp;
   }
 
   // TODO(ajose): Support multiple tracks: http://crbug.com/528523
   if (has_audio_ && !audio_track_index_) {
@@ skipping 213 matching lines @@
     base::TimeTicks timestamp,
     bool is_keyframe)
     : data(std::move(data)),
       alpha_data(std::move(alpha_data)),
       timestamp(timestamp),
       is_keyframe(is_keyframe) {}
 
 WebmMuxer::EncodedVideoFrame::~EncodedVideoFrame() {}
 
 }  // namespace media