GStreamer application to convert a .ogg file to an .mp4 file

Matt Veenstra matt at tribalmedia.com
Mon Jun 6 10:54:20 PDT 2011


Hi William,

When I am trying to debug this cases.
- I try and simplify the pipeline as much as possible.
- I would eliminate the audio or video channel and drop this to a fakesink.
- confirm on_pad_added() being called?
- I specifically link all items myself instead of using
gst_element_link_many() to confirm each step.  And log in between.
- Looking at debug is also very useful, but sometimes overwhelming the
first look.


Cheers,
Matt

On Fri, Jun 3, 2011 at 1:41 PM, William Metcalf <wmetcalf at niftytv.com> wrote:
> I am writing an application to convert a .ogg file to an .mp4 file.  My code
> is below.  I already have the terminal pipeline for completing this task,
> and I am just trying to convert the terminal pipeline into an actual c
> program.  The pipeline seems correct to be, but when I run the application I
> get an error "Internal data stream error".  Does anyone have any suggestions
> as to what is wrong with my code?  Thank you in advance.
>
> #include<gst\gst.h>
> #include<glib-2.0\glib.h>
> #include<string.h>
> #include"Encode_File_Test.h"
> #include"Preprocessor_Defines.h"
>
> /* Handle messages from the pipeline bus */
> static gboolean bus_call(GstBus *bus, GstMessage *msg, gpointer data)
> {
>    GMainLoop *loop = (GMainLoop * ) data;
>
>    switch(GST_MESSAGE_TYPE(msg))
>    {
>        case GST_MESSAGE_EOS:
>            g_print("End of stream\n");
>            g_main_loop_quit(loop);
>            break;
>        case GST_MESSAGE_ERROR:
>            {
>                gchar *debug;
>                GError *error;
>
>                gst_message_parse_error(msg, &error, &debug);
>                g_free(debug);
>
>                g_printerr ("Error: %s\n", error->message);
>                g_error_free(error);
>
>                g_main_loop_quit(loop);
>                break;
>            }
>        default:
>            break;
>    }
>
>    return TRUE;
> }
>
> /* Handles when a pad is added to the demuxer */
> static void on_pad_added(GstElement *element, GstPad *pad, gpointer data)
> {
>    guint result;
>    GstPad *sinkpad;
>    gchar* name;
>    name = gst_pad_get_name(pad);
>
>    result = g_strcasecmp(name, "serial_1fa82364");
>    /* This is the audio pad of the demuxer we need to link it to the
> decoder's audio output in the queue */
>    if(!result)
>    {
>        /* We can now link this pad with the audio decoder's sink pad */
>        g_print("Dynamic pad created, linking the demuxer to the audio
> decoder\n");
>
>        sinkpad = gst_element_get_pad(audio_queue, "sink");
>
>        gst_pad_link(pad, sinkpad);
>
>        gst_object_unref(sinkpad);
>    }
>
>    result = g_strcasecmp(name, "serial_0f0678e1");
>    /* This is the video pad of the demuxer we need to link it to the
> decoder's video output in the queue */
>    if(!result)
>    {
>
>        /* We can now link this pad with the video decoder's sink pad */
>        g_print("Dynamic pad created, linking the demuxer to the video
> decoder\n");
>
>        sinkpad = gst_element_get_static_pad(video_queue, "sink");
>
>        gst_pad_link(pad, sinkpad);
>
>        gst_object_unref(sinkpad);
>    }
> }
>
> /* Connects the src pad of the audio out queue to the audio sink pad of the
> mxuer */
> static void link_audio_to_multiplexer(GstElement *audio_output, GstElement
> *muxer)
> {
>    GstPad *pad, *link_pad;
>
>    link_pad = gst_element_get_static_pad(audio_output, "src");
>
>    pad = gst_element_get_request_pad(muxer, "audio_%d");
>
>    gst_pad_link(link_pad, pad);
>
>    gst_object_unref(pad);
> }
>
> /* Connects the src pad of the video out queue to the video sink pad of the
> muxer */
> static void link_video_to_multiplexer(GstElement *video_output, GstElement
> *muxer)
> {
>    GstPad *pad, *link_pad;
>
>    link_pad = gst_element_get_static_pad(video_output, "src");
>
>    pad = gst_element_get_request_pad(muxer, "video_%d");
>
>    gst_pad_link(link_pad, pad);
>
>    gst_object_unref(pad);
> }
>
> int main (int argc, char *argv[])
> {
>    gst_init(&argc, &argv);
>
>    loop = g_main_loop_new(NULL, FALSE);
>
>    /* Create elements */
>    pipeline            = gst_pipeline_new("audio-player");
>
>    /* Element for reading in a file */
>    source                = gst_element_factory_make("filesrc",
> "file-source");
>
>    /* OGG elements */
>    oggdemuxer            = gst_element_factory_make("oggdemux",
> "ogg-demuxer");
>    vorbis_decoder        = gst_element_factory_make("vorbisdec",
> "vorbis-decoder");
>    theora_decoder        = gst_element_factory_make("theoradec",
> "theora-decoder");
>
>    /* MP4 elements */
>    audio_encoder        = gst_element_factory_make("faac", "aac-encoder");
>    video_encoder        = gst_element_factory_make("ffenc_mpeg4",
> "avc-encoder");
>    mp4_muxer            = gst_element_factory_make("qtmux", "mp4-muxer");
>
>    /* Audio Video elements */
>    audio_converter        = gst_element_factory_make("audioconvert",
> "audio-converter");
>    video_converter        = gst_element_factory_make("ffmpegcolorspace",
> "video-converter");
>    audio_resample        = gst_element_factory_make("audioresample",
> "audio-resample");
>    audio_rate            = gst_element_factory_make("audiorate",
> "audio-rate");
>    videosink            = gst_element_factory_make("autovideosink",
> "video-sink");
>    audiosink            = gst_element_factory_make("autoaudiosink",
> "audio-sink");
>
>    /* Queues */
>    video_queue            = gst_element_factory_make("queue",
> "video-queue");
>    audio_queue            = gst_element_factory_make("queue",
> "audio-queue");
>    video_out_queue        = gst_element_factory_make("queue",
> "video-out-queue");
>    audio_out_queue        = gst_element_factory_make("queue",
> "audio-out-queue");
>
>    /* Element to write to the file */
>    filesink                = gst_element_factory_make("filesink",
> "file-sink");
>
>    /* Make sure we were able to create all of the elements*/
>    if(!pipeline || !source || !oggdemuxer || !vorbis_decoder ||
> !theora_decoder || !audio_encoder || !video_encoder || !mp4_muxer ||
> !audio_converter || !video_converter || !audio_resample || !audio_rate ||
> !videosink || !audiosink || !video_queue || !audio_queue || !video_out_queue
> || !audio_out_queue || !filesink )
>    {
>        g_printerr("One ore more elements could not be created. Exiting.\n");
>        return -1;
>    }
>
>    /* Input file */
>    g_object_set(G_OBJECT(source), "location", "c:\\video.ogg", NULL);
>    g_object_set(G_OBJECT(filesink), "location", "c:\\video(encoded from
> ogg).mp4", NULL);
>
>    /* Add a message handler from pipeline bus */
>    bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
>    gst_bus_add_watch(bus, bus_call, loop);
>    gst_object_unref(bus);
>
>    /* add elements to the pipeline */
>    gst_bin_add_many(GST_BIN(pipeline), source, oggdemuxer, video_queue,
> theora_decoder, video_converter, video_encoder, video_out_queue,
> audio_queue, vorbis_decoder, audio_converter, audio_encoder,
> audio_out_queue, mp4_muxer, filesink, NULL);
>
>    /* link the elements together */
>    gst_element_link(source, oggdemuxer);
>
>    /* video_queue -> theoradec -> ffmpegcolorspace -> ffenc_mpeg4 ->
> video_out_queue ~> qtmux */
>    res = gst_element_link_many(video_queue, theora_decoder, video_converter,
> video_encoder, video_out_queue, NULL);
>    if(!res)
>    {
>        g_printerr("There was a problem linking video elements.\n");
>        return 1;
>    }
>
>    /* queue_audio -> vorbisdec -> audioconvert -> faac -> audio_out_queue ~>
> qtmux */
>    res = gst_element_link_many(audio_queue, vorbis_decoder, audio_converter,
> audio_encoder, audio_out_queue, NULL);
>    if(!res)
>    {
>        g_printerr("There was a problem linking elements.\n");
>        return 1;
>    }
>    g_signal_connect(oggdemuxer, "pad-added", G_CALLBACK(on_pad_added),
> NULL);
>
>    /* qtmux -> filesink */
>    res = gst_element_link(mp4_muxer, filesink);
>
>    link_video_to_multiplexer(video_out_queue, mp4_muxer);
>    link_audio_to_multiplexer(audio_out_queue, mp4_muxer);
>
>
>    /* Set the pipeline stat to play and start the main loop*/
>    g_print("Starting the pipeline\n");
>    gst_element_set_state(pipeline, GST_STATE_PLAYING);
>    g_main_loop_run(loop);
>
>    /* We are done now, do a little bit of cleaning up */
>    g_print("Stopping the pipeline.\n");
>    gst_element_set_state(pipeline, GST_STATE_NULL);
>    gst_object_unref(GST_OBJECT(pipeline));
>
>    return 0;
> }
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>


More information about the gstreamer-devel mailing list