Decode AVPacket

[fre deric]

Hi,
my goal is to demux video in libav and decode it in GStreamer. 

My approach is to take AVPacket from the video stream in the first thread
and send it to GStreamer pipeline in the second thread. Important parts of
code are here:

-- THREAD 1 --
// Take data from AVPacket
img_data = (guchar *)packet.data;
size = packet.size;
// Create gst buffer 
buffer = gst_buffer_new_allocate(NULL, size, NULL);
gst_buffer_map(buffer, &map, GST_MAP_WRITE);
memcpy((guchar *)map.data, img_data, gst_buffer_get_size(buffer));
map.size = size;
gst_buffer_unmap(buffer, &map);
// Send the buffer to appsrc element in the gst pipeline.
gstret = gst_app_src_push_buffer((GstAppSrc *)app_source, buffer);

-- THREAD 2 --
// A video cap for appsrc element
const gchar *video_caps = "video/x-theora, width=1920, height=1080,
framerate=30/1";
// pipeline
string = g_strdup_printf("appsrc name=testsource caps=\"%s\" ! theoradec !
videoconvert ! autovideosink", video_caps);

However I got this error:
"
ERROR from element theoradec0: Could not decode stream.
Debugging info: gsttheoradec.c(812): theora_handle_data_packet ():
/GstPipeline:pipeline0/GstTheoraDec:theoradec0: no header sent yet
"
where theoradec0 is name for theoradec element. 

Why theoradec element is not able to decode the video stream? Does "no
header sent yet" mean, that I am sending data to the pipeline in wrong
format? 

Tested video file:
container: ogg
codec: Theora
dim: 1920x1080
framerate: 30fps


I also tested a version, when the AVPacket was decoded to AVFrame by libav
and then sent to the gstreamer pipeline and it works:

-- THREAD 1 --
// Decode.
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
img_data = (guchar *)pFrame->data
// same way as before.

-- THREAD 2 --
const gchar *video_caps = "video/x-raw, format=BGR, width=1920, height=1080,
framerate=30/1";
string = g_strdup_printf("appsrc name=testsource caps=\"%s\" ! videoconvert
! autovideosink", video_caps);

Thank you.





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