decodifica un video mp4 con gstreamer

Question

Voglio riprodurre un video mp4 in Gstreamer, ma ho riscontrato un errore con x264dec che non è stato trovato. Ho scritto questa pipeline

gst-launch filesrc \ 
    location=/media/thesis/Gstreamer/pub_Irma.mp4 \ 
    ! qtdemux name=demux demux. ! queue ! faad \ 
    ! audioconvert ! audioresample ! autoaudiosink demuxer. \ 
    ! queue ! x264dec ! ffmpegcolorspace ! autovideosink 

Dopo questo passaggio, il mio obiettivo è generare tracce di esecuzione di una decodifica video mp4. Non so dove sia il problema con x264dec.

Answer 1

Non penso ci sia un elemento x264dec (so solo dell'elemento x264enc). Si potrebbe desiderare di utilizzare ffdec_h264 come in this nabble post:

gst-launch-0.10 filesrc location=$1 ! h264parse ! ffdec_h264 ! ffmpegcolorspace ! deinterlace ! xvimagesink 

Answer 2

Questo potrebbe essere più facile:

gst-launch-0.10 playbin2 uri=file:///path/to/foo.mp4 

o

gst-launch-1.0 playbin uri=file:///path/to/foo.mp4 

(hai ancora bisogno gli elementi necessari installati ovviamente).

Answer 3

Questo comando

gst-launch-0.10 filesrc location=/root/gstreamerexamples/big.mp4 ! qtdemux name=demux demux. ! queue ! faad ! audioconvert ! audioresample ! autoaudiosink demux. ! queue ! ffdec_h264 ! ffmpegcolorspace ! autovideosink

funziona bene per me.

Per riprodurre file mp4, prendere il video mp4 bigBuckBunny come file di test. Quindi assicurati che tutti gli elementi menzionati nel gst-launch siano costruiti su x86 o su qualsiasi altra piattaforma di destinazione.

Si prega di inviare molto tempo nella corretta installazione di GStreamer.

Answer 4

#include <gst/gst.h> 

    typedef struct _CustomData { 
    GstElement *pipeline; 
    GstElement *source; 
    GstElement *demuxer; 
    GstElement *audioqueue; 
    GstElement *videoqueue; 
    GstElement *audio_decoder; 
    GstElement *video_decoder; 
    GstElement *video_convert; 
    GstElement *audio_convert; 
    GstElement *video_sink; 
    GstElement *audio_sink; 
    } CustomData; 


    static void pad_added_handler (GstElement *src, GstPad *pad, CustomData *data); 

    int main(int argc, char *argv[]) { 
    CustomData data; 
    GstBus *bus; 
    GstMessage *msg; 
    GstStateChangeReturn ret; 
    gboolean terminate = FALSE; 
    /* Initialize GStreamer */ 
    gst_init (&argc, &argv); 
    /* Create the elements */ 
    data.source = gst_element_factory_make ("filesrc", "source"); 
    data.demuxer = gst_element_factory_make ("oggdemux", "demuxer"); 
    data.audioqueue = gst_element_factory_make("queue","audioqueue"); 
    data.videoqueue = gst_element_factory_make("queue","videoqueue"); 
    data.audio_decoder = gst_element_factory_make ("vorbisdec", "audio_decoder"); 
    data.audio_convert = gst_element_factory_make ("audioconvert", "audio_convert"); 
    data.audio_sink = gst_element_factory_make ("autoaudiosink", "audio_sink"); 
    data.video_decoder = gst_element_factory_make("theoradec","video_decoder"); 
    data.video_convert = gst_element_factory_make("ffmpegcolorspace","video_convert"); 
    data.video_sink = gst_element_factory_make("autovideosink","video_sink"); 

    data.pipeline = gst_pipeline_new ("test-pipeline"); 
    if (!data.pipeline || !data.source || !data.demuxer || !data.audioqueue ||!data.audio_decoder ||!data.audio_convert || 
    !data.audio_sink || !data.videoqueue || !data.video_decoder || !data.video_convert || !data.video_sink) { 
    g_printerr ("Not all elements could be created.\n"); 
    return -1; 
    } 

    gst_bin_add_many (GST_BIN (data.pipeline), data.source,data.demuxer,data.audioqueue,data.audio_decoder,data.audio_convert,data.audio_sink,data.videoqueue,data.video_decoder,data.video_convert,data.video_sink, NULL); 

    if (!gst_element_link(data.source,data.demuxer)) { 
    g_printerr ("Elements could not be linked.\n"); 
    gst_object_unref (data.pipeline); 
    return -1; 
    } 

    if (!gst_element_link_many (data.audioqueue,data.audio_decoder,data.audio_convert, data.audio_sink,NULL)) { 
    g_printerr (" audio Elements could not be linked.\n"); 
    gst_object_unref (data.pipeline); 
    return -1; 
    } 
    if (!gst_element_link_many(data.videoqueue,data.video_decoder,data.video_convert, data.video_sink,NULL)) { 
    g_printerr("video Elements could not be linked.\n"); 
    gst_object_unref(data.pipeline); 
    return -1; 
    } 
    /* Set the file to play */ 
    g_object_set (data.source, "location", argv[1], NULL); 

    g_signal_connect (data.demuxer, "pad-added", G_CALLBACK (pad_added_handler), &data); 
    /* Start playing */ 
    ret = gst_element_set_state (data.pipeline, GST_STATE_PLAYING); 
    if (ret == GST_STATE_CHANGE_FAILURE) { 
    g_printerr ("Unable to set the pipeline to the playing state.\n"); 
    gst_object_unref (data.pipeline); 
    return -1; 
    } 
    /* Listen to the bus */ 
    bus = gst_element_get_bus (data.pipeline); 
    do { 
    msg = gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE, 
    GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS); 

    if (msg != NULL) { 
    GError *err; 
    gchar *debug_info; 
    switch (GST_MESSAGE_TYPE (msg)) { 
    case GST_MESSAGE_ERROR: 
    gst_message_parse_error (msg, &err, &debug_info); 
    g_printerr ("Error received from element %s: %s\n", GST_OBJECT_NAME (msg->src), err->message); 
    g_printerr ("Debugging information: %s\n", debug_info ? debug_info : "none"); 
    g_clear_error (&err); 
    g_free (debug_info); 
    terminate = TRUE; 
    break; 
    case GST_MESSAGE_EOS: 
    g_print ("End-Of-Stream reached.\n"); 
    terminate = TRUE; 
    break; 
    case GST_MESSAGE_STATE_CHANGED: 

    if (GST_MESSAGE_SRC (msg) == GST_OBJECT (data.pipeline)) { 
    GstState old_state, new_state, pending_state; 
    gst_message_parse_state_changed (msg, &old_state, &new_state, &pending_state); 
    g_print ("Pipeline state changed from %s to %s:\n", 
    gst_element_state_get_name (old_state), gst_element_state_get_name (new_state)); 
    } 
    break; 
    default: 

    g_printerr ("Unexpected message received.\n"); 
    break; 
    } 
    gst_message_unref (msg); 
    } 
    } while (!terminate); 

    gst_object_unref (bus); 
    gst_element_set_state (data.pipeline, GST_STATE_NULL); 
    gst_object_unref (data.pipeline); 
    return 0; 
    } 

    /* This function will be called by the pad-added signal */ 
    static void pad_added_handler (GstElement *src, GstPad *new_pad, CustomData *data) { 
    g_print("Inside the pad_added_handler method \n"); 
    GstPad *sink_pad_audio = gst_element_get_static_pad (data->audioqueue, "sink"); 
    GstPad *sink_pad_video = gst_element_get_static_pad (data->videoqueue, "sink"); 

    GstPadLinkReturn ret; 
    GstCaps *new_pad_caps = NULL; 
    GstStructure *new_pad_struct = NULL; 
    const gchar *new_pad_type = NULL; 
    g_print ("Received new pad '%s' from '%s':\n", GST_PAD_NAME (new_pad), GST_ELEMENT_NAME (src)); 



    new_pad_caps = gst_pad_get_caps (new_pad); 
    new_pad_struct = gst_caps_get_structure (new_pad_caps, 0); 
    new_pad_type = gst_structure_get_name (new_pad_struct); 


    if (g_str_has_prefix (new_pad_type,"audio/x-vorbis" /*"audio/mpeg"*/)) 
    { 
     ret = gst_pad_link (new_pad, sink_pad_audio); 
     if (GST_PAD_LINK_FAILED (ret)) 
     { 
     g_print (" Type is '%s' but link failed.\n", new_pad_type); 
     } 
     else 
     { 
     g_print (" Link succeeded (type '%s').\n", new_pad_type); 
     } 
    } 



    else if (g_str_has_prefix (new_pad_type, "video/x-theora"/*"video/x-h264"*/)) 
    { 
     ret = gst_pad_link (new_pad, sink_pad_video); 

     if (GST_PAD_LINK_FAILED (ret)) 
     { 
     g_print (" Type is '%s' but link failed.\n", new_pad_type); 
     } 
     else 
     { 
     g_print (" Link succeeded (type '%s').\n", new_pad_type); 
     } 
    } 


    else { 
    g_print (" It has type '%s' which is not raw audio. Ignoring.\n", new_pad_type); 
    goto exit; 
    } 
    exit: 
    if (new_pad_caps != NULL) 
    gst_caps_unref (new_pad_caps); 
    gst_object_unref (sink_pad_audio); 
    gst_object_unref (sink_pad_video); 
    } 

Answer 5

Ho un nome di file tuhi.mp4 nel desktop. Quindi il comando va in questo modo.

$ gst-launch-1.0 filesrc location=~/Desktop/tuhi.mp4 ! decodebin name=dec ! videoconvert ! autovideosink dec. ! audioconvert ! audioresample ! alsasink 

Answer 6

Ho un file ogg sul desktop, quindi il comando va in questo modo.

$ gst-launch-1.0 filesrc location=~/Desktop/test.ogg ! oggdemux name=demuxer \ 
    demuxer. ! queue ! vorbisdec ! audioconvert ! audioresample ! autoaudiosink \ 
    demuxer. ! queue ! theoradec ! videoconvert ! autovideosink 

Ciò funzionerà anche per GStreamer 0.10, ma su base annua bisogno di sostituire videoconvert con ffmpegcolorspace