Use av_rescale_q() for converting FFmpeg timestamps to base::TimeDelta.

media/base/media_posix.cc

 // Copyright (c) 2009 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/base/media.h"
 
 #include <string>
 
 #include <dlfcn.h>
 
@@ skipping 104 matching lines @@
 void* (*av_malloc_ptr)(unsigned int size) = NULL;
 void* av_malloc(unsigned int size) {
   return av_malloc_ptr(size);
 }
 
 void (*av_free_ptr)(void* ptr) = NULL;
 void av_free(void* ptr) {
   return av_free_ptr(ptr);
 }
 
+int64_t (*av_rescale_q_ptr)(int64_t a, AVRational bq, AVRational cq) = NULL;
+int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) {
+  return av_rescale_q_ptr(a, bq, cq);
+}
+
 }  // extern "C"
 
 
 namespace media {
 
 namespace {
 
 enum FFmpegDSOKeys {
   FILE_LIBAVCODEC,       // full path to libavcodec media decoding library.
   FILE_LIBAVFORMAT,      // full path to libavformat media parsing library.
@@ skipping 98 matching lines @@
   av_register_protocol_ptr =
       reinterpret_cast<int (*)(URLProtocol*)>(
           dlsym(libs[FILE_LIBAVFORMAT], "av_register_protocol"));
 
   av_malloc_ptr =
       reinterpret_cast<void* (*)(unsigned int)>(
           dlsym(libs[FILE_LIBAVUTIL], "av_malloc"));
   av_free_ptr =
       reinterpret_cast<void (*)(void*)>(
           dlsym(libs[FILE_LIBAVUTIL], "av_free"));
+  av_rescale_q_ptr =
+      reinterpret_cast<int64_t (*)(int64_t, AVRational, AVRational)>(
+          dlsym(libs[FILE_LIBAVUTIL], "av_rescale_q"));
 
   // Check that all the symbols were loaded correctly before returning true.
   if (av_get_bits_per_sample_format_ptr &&
       avcodec_init_ptr &&
       avcodec_find_decoder_ptr &&
       avcodec_thread_init_ptr &&
       avcodec_open_ptr &&
       avcodec_alloc_frame_ptr &&
       avcodec_decode_audio2_ptr &&
       avcodec_decode_video_ptr &&
 
       av_register_all_ptr &&
       av_open_input_file_ptr &&
       av_find_stream_info_ptr &&
       av_read_frame_ptr &&
       av_seek_frame_ptr &&
       av_register_protocol_ptr &&
 
       av_malloc_ptr &&
-      av_free_ptr) {
+      av_free_ptr &&
+      av_rescale_q_ptr) {
     return true;
   }
 
   return false;
 }
 
 }  // namespace media