Replace media::Limits struct with media::limits namespace and update documentation.

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2011 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 "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 502 matching lines @@
   }
   if (format_context_->duration != static_cast<int64_t>(AV_NOPTS_VALUE)) {
     // If there is a duration value in the container use that to find the
     // maximum between it and the duration from A/V streams.
     const AVRational av_time_base = {1, AV_TIME_BASE};
     max_duration =
         std::max(max_duration,
                  ConvertFromTimeBase(av_time_base, format_context_->duration));
   } else {
     // The duration is not a valid value. Assume that this is a live stream
     // and set duration to the maximum int64 number to represent infinity.

[Ami GONE FROM CHROMIUM, 2011/12/03 02:11:38]

This is crazy.  If we want \infty we should define a kInfinity, and probably use
an obviously-bogus value like -1.

[scherkus (not reviewing), 2011/12/06 02:05:57]

That makes sense for durations, but if we're going to pick sentinel values why
not use a value that's as close to infinity as we're going to get? it has the
nice property of being able to use std::max()/min()

     max_duration = base::TimeDelta::FromMicroseconds(
-        Limits::kMaxTimeInMicroseconds);
+        limits::kMaxTimeInMicroseconds);
   }
 
   // Some demuxers, like WAV, do not put timestamps on their frames. We
   // assume the the start time is 0.
   if (start_time_ == kNoTimestamp)
     start_time_ = base::TimeDelta();
 
   // Good to go: set the duration and bitrate and notify we're done
   // initializing.
   if (host())
@@ skipping 19 matching lines @@
   for (size_t i = 0; i < format_context_->nb_streams; ++i) {
     AVCodecContext* codec_context = format_context_->streams[i]->codec;
     bitrate += codec_context->bit_rate;
   }
   if (bitrate > 0)
     return bitrate;
 
   // If there isn't a bitrate set in the container or streams, but there is a
   // valid duration, approximate the bitrate using the duration.
   if (max_duration_.InMilliseconds() > 0 &&
-      max_duration_.InMicroseconds() < Limits::kMaxTimeInMicroseconds) {
+      max_duration_.InMicroseconds() < limits::kMaxTimeInMicroseconds) {

[Ami GONE FROM CHROMIUM, 2011/12/03 02:11:38]

This would be a lot clearer as != kInfinity IMO.

[scherkus (not reviewing), 2011/12/06 02:05:57]

Done.

     int64 filesize_in_bytes;
     if (GetSize(&filesize_in_bytes))
       return 8000 * filesize_in_bytes / max_duration_.InMilliseconds();

[Ami GONE FROM CHROMIUM, 2011/12/03 02:11:38]

This can SIGFPE b/c the >0 check is done in microseconds but here we divide by
milliseconds.

[scherkus (not reviewing), 2011/12/06 02:05:57]

Done.

   }
 
   // Bitrate could not be determined.
   return 0;
 }
 
 bool FFmpegDemuxer::IsLocalSource() {
   return local_source_;
 }
 
@@ skipping 153 matching lines @@
   read_event_.Wait();
   return last_read_bytes_;
 }
 
 void FFmpegDemuxer::SignalReadCompleted(size_t size) {
   last_read_bytes_ = size;
   read_event_.Signal();
 }
 
 }  // namespace media