Hand-apply cb998bee2e70f3426fd95655736deae803efa58e from master; examine a whole...

[dcpomatic.git] / src / lib / ffmpeg_examiner.cc

diff --git a/src/lib/ffmpeg_examiner.cc b/src/lib/ffmpeg_examiner.cc
index 62b909b1d65f3708293ca8dcbe91fe4a371d4608..f28060a56da356d30f48295db8c4e9d0444cb56a 100644 (file)
--- a/src/lib/ffmpeg_examiner.cc
+++ b/src/lib/ffmpeg_examiner.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -26,18 +26,19 @@ extern "C" {
 #include "ffmpeg_audio_stream.h"
 #include "ffmpeg_subtitle_stream.h"
 #include "util.h"
+#include "safe_stringstream.h"
 
 #include "i18n.h"
 
 using std::string;
 using std::cout;
 using std::max;
-using std::stringstream;
 using boost::shared_ptr;
 using boost::optional;
 
 FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c)
        : FFmpeg (c)
+       , _need_video_length (false)
 {
        /* Find audio and subtitle streams */
 
@@ -64,6 +65,12 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c)
                }
        }
 
+       /* See if the header has duration information in it */
+       _need_video_length = _format_context->duration == AV_NOPTS_VALUE;
+       if (!_need_video_length) {
+               _video_length = ContentTime::from_seconds (double (_format_context->duration) / AV_TIME_BASE);
+       }
+
        /* Run through until we find:
         *   - the first video.
         *   - the first audio for each stream.
@@ -104,13 +111,18 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c)
 void
 FFmpegExaminer::video_packet (AVCodecContext* context)
 {
-       if (_first_video) {
+       if (_first_video && !_need_video_length) {
                return;
        }
 
        int frame_finished;
        if (avcodec_decode_video2 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
-               _first_video = frame_time (_format_context->streams[_video_stream]);
+               if (!_first_video) {
+                       _first_video = frame_time (_format_context->streams[_video_stream]);
+               }
+               if (_need_video_length) {
+                       _video_length = frame_time (_format_context->streams[_video_stream]).get_value_or (ContentTime ());
+               }
        }
 }
 
@@ -156,7 +168,7 @@ FFmpegExaminer::frame_time (AVStream* s) const
        return t;
 }
 
-float
+optional<float>
 FFmpegExaminer::video_frame_rate () const
 {
        /* This use of r_frame_rate is debateable; there's a few different
@@ -176,14 +188,25 @@ FFmpegExaminer::video_size () const
 ContentTime
 FFmpegExaminer::video_length () const
 {
-       ContentTime const length = ContentTime::from_seconds (double (_format_context->duration - _format_context->start_time) / AV_TIME_BASE);
-       return ContentTime (max (ContentTime::Type (1), length.get ()));
+       ContentTime const length = ContentTime::from_seconds (double (_format_context->duration) / AV_TIME_BASE);
+       return ContentTime (max (ContentTime (1), _video_length));
+}
+
+optional<float>
+FFmpegExaminer::sample_aspect_ratio () const
+{
+       AVRational sar = av_guess_sample_aspect_ratio (_format_context, _format_context->streams[_video_stream], 0);
+       if (sar.num == 0) {
+               /* I assume this means that we don't know */
+               return optional<float> ();
+       }
+       return float (sar.num) / sar.den;
 }
 
 string
 FFmpegExaminer::audio_stream_name (AVStream* s) const
 {
-       stringstream n;
+       SafeStringStream n;
 
        n << stream_name (s);
 
@@ -199,7 +222,7 @@ FFmpegExaminer::audio_stream_name (AVStream* s) const
 string
 FFmpegExaminer::subtitle_stream_name (AVStream* s) const
 {
-       stringstream n;
+       SafeStringStream n;
 
        n << stream_name (s);
 
@@ -213,7 +236,7 @@ FFmpegExaminer::subtitle_stream_name (AVStream* s) const
 string
 FFmpegExaminer::stream_name (AVStream* s) const
 {
-       stringstream n;
+       SafeStringStream n;
 
        if (s->metadata) {
                AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);