fall back to use video-duration from container if stream duration is n/a

this fixes issues with some .mkv files encoded with
libebml v1.2.0 + libmatroska v1.1.0

diff --git a/gtk2_ardour/transcode_ffmpeg.cc b/gtk2_ardour/transcode_ffmpeg.cc
index 35a0302be706df841dc6d2a361ea995f410fffd4..2883f87866598405967f7589600128ac5c72b5eb 100644 (file)
--- a/gtk2_ardour/transcode_ffmpeg.cc
+++ b/gtk2_ardour/transcode_ffmpeg.cc
@@ -138,9 +138,20 @@ TranscodeFfmpeg::probe ()
                } \
        }
 
+       std::string duration_from_format;
+
        for (std::vector<std::vector<std::string> >::iterator i = lines.begin(); i != lines.end(); ++i) {
                if (i->at(0) == X_("format")) {
                        /* format,filename,#streams,format-name,format-long-name,start-time,duration,size,bitrate */
+                       for (std::vector<std::string>::iterator kv = i->begin(); kv != i->end(); ++kv) {
+                               const size_t kvsep = kv->find('=');
+                               if(kvsep == std::string::npos) continue;
+                               std::string key = kv->substr(0, kvsep);
+                               std::string value = kv->substr(kvsep + 1);
+                               if (key == X_("duration")) {
+                                       duration_from_format = value;
+                               }
+                       }
                } else
                if (i->at(0) == X_("stream")) {
                        if (i->at(5) == X_("codec_type=video") && m_width == 0) {
@@ -172,7 +183,7 @@ TranscodeFfmpeg::probe ()
                                                PARSE_FRACTIONAL_FPS(m_fps)
                                        } else if (key == X_("time_base")) {
                                                PARSE_FRACTIONAL_FPS(timebase)
-                                       } else if (key == X_("timecode") && m_duration == 0) {
+                                       } else if (key == X_("timecode") && m_duration == 0 && m_fps > 0) {
                                                int h,m,s; char f[32];
                                                if (sscanf(i->at(16).c_str(), "%d:%d:%d:%32s",&h,&m,&s,f) == 4) {
                                                        m_duration = (ARDOUR::framecnt_t) floor(m_fps * (
@@ -239,6 +250,11 @@ TranscodeFfmpeg::probe ()
        }
        /* end parse */
 
+       if (m_duration == 0 && !duration_from_format.empty() && m_fps > 0) {
+               warning << "using video-duration from format (container)." << endmsg;
+               m_duration = atof(duration_from_format) * m_fps;
+       }
+
 #if 0 /* DEBUG */
        printf("FPS: %f\n", m_fps);
        printf("Duration: %lu frames\n",(unsigned long)m_duration);