[gst-devel] Seek works strangely with filesink

[Aurelien Grimaud]

Hi,
audiosink is sync on the clock, not filesink.
So your pipeline with filesink runs as fast as possible, while the 
audiosink one runs at real time.
Your filesink pipelines misses a sync element.
Try add identity with sync=TRUE in it to force clock sync.

gst-launch -v filesrc location=/home/musique/Heidsieck-Bernard.mp3 \
! decodebin ! identity sync=TRUE ! wavenc ! filesink location=/tmp/xx.wav

Note:
I was first expecting sync option on filesink to do the trick, but it 
fails :
gst-launch -v filesrc location=/home/musique/Heidsieck-Bernard.mp3 \
! decodebin ! wavenc ! identity ! filesink location=/tmp/xx.wav sync=TRUE

So I tried
gst-launch -v filesrc location=/home/musique/Heidsieck-Bernard.mp3 \
! decodebin ! wavenc ! identity sync=TRUE ! filesink location=/tmp/xx.wav
but it runs too fast too.

Aurelien

David Banks a écrit :
> Hi, I'm just getting started with GStreamer.  I want to write a program to load
> an Ogg file, play it, and seek to a random point within the file every two
> seconds.  In addition, I want to be able to save the output of the program to a
> file.
>
> I initially wrote the program using the pipeline:
>
> filesrc | oggdemux | vorbisdec | audioconvert | autoaudiosink
>
> Basically according to the example given in the application development manual.
> I added the function 'cb_timeout0' to detect the length and do the seek.  That
> version worked perfectly and produced exactly what I expected.
>
> I then tried to make it write its output to a file.  I initially tried to simply
> replace 'autoaudiosink' with 'filesink', but couldn't figure out the format of
> the raw samples in the output file.  Since I wanted WAV output anyway, I tried
> using wavenc.  After a little trial and error, I found the pipeline below:
>
> filesrc | oggdemux | vorbisdec | audioconvert | wavenc | filesink
>
> I converted it to the program below.  This program displays an odd behaviour,
> however.  Its output is always the size of the fully decoded Ogg file, no matter
> where you interrupt it.  That is, even if you run it for only a few seconds
> (when it .  In addition, the seeks in the output are erratic.  For
> example, if you run the program for three minutes, the output file might contain
> only three or four seeks.  They seem to occur at random points in the output.
>
> Why is the filesink output so different from the autoaudiosink output?  Is it
> possible the seeks are happening in the *output* rather than the input file?  I
> tried replacing the first parameter to gst_element_seek() with a pointer to the
> demuxer rather than the entire pipeline, but still the same behaviour.
>
> // gcc -o demo -Wall -g $(pkg-config --libs --cflags $(libs)) demo.c
>
> #include <stdio.h>
>
> #include <gst/gst.h>
> #include <glib.h>
>
> static gboolean cb_bus(GstBus *bus, GstMessage *msg, gpointer data);
> static void cb_pad_added(GstElement *element, GstPad *pad, gpointer data);
> gboolean cb_timeout0(gpointer data);
>
> gint32 pos = 0;
>
> int main(int argc, char **argv) {
>     GMainLoop *loop;
>     GstElement *pipeline, *source, *demuxer, *decoder, *conv1, *conv2, *sink;
>     GstBus *bus;
>
>     gst_init(&argc, &argv);
>     loop = g_main_loop_new(NULL, FALSE);
>
>     if (argc != 2) {
>         g_printerr("Usage: %s <ogg vorbis filename>\n", argv[0]);
>         return 1;
>     }
>
>     pipeline = gst_pipeline_new("audio-player");
>     source = gst_element_factory_make("filesrc", "file-source");
>     demuxer = gst_element_factory_make("oggdemux", "ogg-demuxer");
>     decoder = gst_element_factory_make("vorbisdec", "vorbis-decoder");
>     conv1    = gst_element_factory_make("audioconvert", NULL);
>     conv2    = gst_element_factory_make("wavenc", NULL);
>     sink    = gst_element_factory_make("filesink", "audio-output");
>
>     if (!pipeline || !source || !demuxer || !decoder || !conv1 ||
> !conv2 || !sink) {
>         g_printerr("pipeline failed to create properly, exiting\n");
>         return 1;
>     }
>
>     g_object_set(G_OBJECT(source), "location", argv[1], NULL);
>     g_object_set(G_OBJECT(sink), "location", "/home/amoe/foo.wav", NULL);
>
>     bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
>     gst_bus_add_watch(bus, cb_bus, loop);
>     gst_object_unref(bus);
>
>     gst_bin_add_many(
>         GST_BIN(pipeline),
>         source, demuxer, decoder, conv1, conv2, sink, NULL
>     );
>
>     gst_element_link(source, demuxer);
>     gst_element_link_many(decoder, conv1, conv2, sink, NULL);
>
>
>     g_signal_connect(
>         demuxer, "pad-added", G_CALLBACK(cb_pad_added), decoder
>     );
>
>     g_print("Now playing: %s\n", argv[1]);
>     gst_element_set_state(pipeline, GST_STATE_PLAYING);
>
>     // seek
>     g_timeout_add(2 * 1000, cb_timeout0, pipeline);
>
>     g_print("running...\n");
>     g_main_loop_run(loop);
>
>     g_print("returned, stopping playback\n");
>     gst_element_set_state(pipeline, GST_STATE_NULL);
>
>     g_print("deleting pipeline\n");
>     gst_object_unref(GST_OBJECT(pipeline));
>
>     return 0;
> }
>
> gboolean cb_timeout0(gpointer data) {
>     GstElement *pipeline = (GstElement *) data;
>     GstFormat fmt = GST_FORMAT_TIME;
>     gboolean test;
>     gint64 len;
>     guint64 len_seconds;
>
>     test = gst_element_seek(
>         pipeline,
>         1.0,
>         GST_FORMAT_TIME,
>         GST_SEEK_FLAG_FLUSH,
>         GST_SEEK_TYPE_SET,
>         pos * GST_SECOND,
>         GST_SEEK_TYPE_NONE,
>         -1
>         );
>     printf("seek: %d\n", test);
>
>     test = gst_element_query_duration(
>         pipeline, &fmt, &len
>     );
>
>     len_seconds = len / GST_SECOND;
>     printf("total time: %lld (%llds)\n", len, len_seconds);
>     pos = g_random_int_range(0, len_seconds);
>     printf("random: %d\n", pos);
>
>     puts("timeout called");
>
>     return TRUE;
> }
>
> static gboolean cb_bus(GstBus *bus, GstMessage *msg, gpointer data) {
>
>     return TRUE;
> }
>
> static void cb_pad_added(GstElement *element, GstPad *pad, gpointer data) {
>
>     GstPad *sinkpad;
>     GstElement *decoder = (GstElement *) data;
>
>     puts("pad added callback");
>     g_print("dynamic pad created, linking demuxer/decoder\n");
>
>     sinkpad = gst_element_get_static_pad(decoder, "sink");
>     gst_pad_link(pad, sinkpad);
>
>     gst_object_unref(sinkpad);
>
> }
>
> Thanks,
>