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This post was updated on .
Hello,
I have to play raw audio files with GStreamer and manage the time position of the audio stream (setting and monitoring the time position). To manage that time position, I also need the duration of the audio file, which GStreamer apparently cannot get or calculate. I understand that raw data doesn't have a header with meta-data (like wav files for example) but I thought that maybe with the capabilities given (signed 16 bit, little-endian, ...), GStreamer would succeed to get that duration.
So here is my question: how can I get that duration? Or how can I force GStreamer to set a given duration to the file I'm playing?
Below is my code that doesn't manage to get a proper duration (it always returns 0 as a duration)
I'll be really thankful for any help or advice!
--
Thibaud
[Code]
Here is the function that plays the raw audio file.
{
// Create pipeline for raw audio data
QString str_audioPipeline = "filesrc location=myrawaudiofile.raw ! audio/x-raw,format=S16LE,rate=48000,channels=2 ! directsoundsink";
// Gstreamer initialisation
gst_init(NULL, NULL);
// Parse pipeline
GError * message = NULL;
audioPlaybackPipeline = gst_parse_launch(str_audioPipeline.toStdString().c_str(), &message);
// Set callback to get position and length of the stream
playbackTrackerID = g_timeout_add(200, (GSourceFunc)get_position, audioPlaybackPipeline);
// Set bus to get messages notifications
GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(audioPlaybackPipeline));
gst_bus_add_watch(bus, playback_bus_callback, NULL);
gst_object_unref(bus);
// Set the playback pipeline state to PLAYING
gst_element_set_state(audioPlaybackPipeline, GST_STATE_PLAYING);
// Check if the pipeline state changed with success
if (gst_element_get_state(audioPlaybackPipeline, NULL, NULL, -1) == GST_STATE_CHANGE_FAILURE)
{
// AUDIO Playback::ERROR: Failed to go into PLAYING state
return false;
}
else
{
// Create a GLib Main Loop and set it to run
playbackLoop = g_main_loop_new(NULL, NULL);
g_main_loop_run(playbackLoop);
return true;
}
}
Here is the callback used to get the position and duration of the stream
gboolean get_position(GstElement *pipeline)
{
// Get the current position
gst_element_query_position(pipeline, GST_FORMAT_TIME, &playbackPosition);
// Get the duration
gst_element_query_duration(pipeline, GST_FORMAT_TIME, &playbackDuration);
}
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