Encoding raw data from buffere and store encoded data in another buffer

aasim mdamirraza at gmail.com
Tue May 8 04:42:48 UTC 2018


Hi guys,

I have very less experience in gstreamer api level code.
kindly help me or guide in right path.

Problem:

I want to inject the buffer (two buffer's ) containing YUV data & PCM data
(read from .yuv & .pcm files) to gstreamer-1.0 pipe line. 


Error:
I am getting error in linking the elements.
"Elements could not be linked" 





#include <gst/gst.h>
#include <gst/audio/audio.h>
#include <gst/app/gstappsrc.h>
#include <gst/base/gstpushsrc.h>
#include <gst/app/gstappsink.h>
#include <string.h>
#include <stdio.h>

#define CHUNK_SIZE 4096   /* Amount of bytes we are sending in each buffer
*/
#define SAMPLE_RATE 48000 /* Samples per second we are sending */

/* Structure to contain all our information, so we can pass it to callbacks
*/
typedef struct _CustomData {
	GstElement *pipeline, *app_source, *tee, *audio_queue, *audio_convert1,
		*audio_resample, *audio_sink;//*app_decode,*audio_decode;
	GstElement *app_queue, *audio_convert2, *app_sink;


	guint64 num_samples;   /* Number of samples generated so far (for
						   timestamp generation) */
						   //  gfloat a, b, c, d;     /* For waveform generation */

	guint sourceid;        /* To control the GSource */
	FILE *fp, *fp1;
	GMainLoop *main_loop;  /* GLib's Main Loop */
} CustomData;

/* This method is called by the idle GSource in the mainloop, to feed
CHUNK_SIZE bytes into appsrc.
* The ide handler is added to the mainloop when appsrc requests us to start
sending data (need-data signal)
* and is removed when appsrc has enough data (enough-data signal).
*/
static gboolean push_data(CustomData *data) {
	GstBuffer *buffer;
	GstFlowReturn ret;
	int i, r;
	GstMapInfo map;
	printf("sujith2222");
	gint num_samples = CHUNK_SIZE / 2; /* Because each sample is 16 bits */
									   //gfloat freq;

									   /* Create a new empty buffer */
	buffer = gst_buffer_new_and_alloc(CHUNK_SIZE);

	/* Set its timestamp and duration */
	GST_BUFFER_TIMESTAMP(buffer) = gst_util_uint64_scale(data->num_samples,
		GST_SECOND, SAMPLE_RATE);
	GST_BUFFER_DURATION(buffer) = gst_util_uint64_scale(CHUNK_SIZE,
		GST_SECOND, SAMPLE_RATE);

	/* Generate some psychodelic waveforms */
	gst_buffer_map(buffer, &map, GST_MAP_WRITE);
	r = fread(map.data, 2, CHUNK_SIZE / 2, data->fp);
	gst_buffer_unmap(buffer, &map);
	data->num_samples += num_samples;

	while (r == NULL)
		gst_app_src_end_of_stream((GstAppSrc *)(data->app_source));



	/* Push the buffer into the appsrc */
	g_signal_emit_by_name(data->app_source, "push-buffer", buffer, &ret);
	// gst_app_src_end_of_stream (data->app_source);
	//gst_app_src_push_buffer (data->app_source, buffer);
	/* Free the buffer now that we are done with it */
	gst_buffer_unref(buffer);

	if (ret != GST_FLOW_OK) {
		/* We got some error, stop sending data */
		return FALSE;
	}

	return TRUE;
}

/* This signal callback triggers when appsrc needs data. Here, we add an
idle handler
* to the mainloop to start pushing data into the appsrc */
static void start_feed(GstElement *source, guint size, CustomData *data) {
	if (data->sourceid == 0) {
		g_print("Start feeding\n");
		data->sourceid = g_idle_add((GSourceFunc)push_data, data);
	}
}

/* This callback triggers when appsrc has enough data and we can stop
sending.
* We remove the idle handler from the mainloop */
static void stop_feed(GstElement *source, CustomData *data) {
	if (data->sourceid != 0) {
		g_print("Stop feeding\n");
		g_source_remove(data->sourceid);
		data->sourceid = 0;
	}
}

/* The appsink has received a buffer */

static void new_sample(GstElement *sink, CustomData *data) {

	printf("sujith1111111");
	GstSample *sample;
	///////////////////////////////////////////////////////
	GstBuffer *buffer;
	GstMapInfo map;
	g_signal_emit_by_name(data->app_sink, "pull-sample", &sample, NULL);
	if (sample)
	{
		buffer = gst_sample_get_buffer(sample);

		gst_buffer_map(buffer, &map, GST_MAP_READ);

		g_print("\n here size=%d\n", map.size);
		fwrite(map.data, 1, map.size, data->fp1); ///data is written to a file
		gst_buffer_unmap(buffer, &map);
		gst_sample_unref(sample);

		/////////////////////////////////////////////////
	}
}

/* This function is called when an error message is posted on the bus */
static void error_cb(GstBus *bus, GstMessage *msg, CustomData *data) {
	GError *err;
	gchar *debug_info;

	/* Print error details on the screen */
	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);

	g_main_loop_quit(data->main_loop);
}

int main1(int argc, char *argv[]) {
	CustomData data;
	GstPad *tee_audio_pad, *tee_app_pad;
	GstPad *queue_audio_pad, *queue_app_pad;
	GstAudioInfo info;
	GstCaps *audio_caps;
	GstBus *bus;

	/* Initialize cumstom data structure */
	memset(&data, 0, sizeof(data));
	//data.fp=fopen("/songs/ChoosiChudangane.mp3","rb");
	data.fp = fopen("E:/pocVR/ConsoleApplication6/x64/Transformers1080p.pcm",
"rb");
	if (data.fp == NULL)
	{
		printf("\n not bale to open input file \n");
	}
	data.fp1 = fopen("1.raw", "wb");
	/* Initialize GStreamer */
	gst_init(&argc, &argv);

	/* Create the elements */
	data.app_source = gst_element_factory_make("appsrc", "audio_source");
	data.tee = gst_element_factory_make("tee", "tee");
	data.audio_queue = gst_element_factory_make("queue", "audio_queue");
	//data.app_decode = gst_element_factory_make ("decodebin", "app_decode");
	data.audio_convert1 = gst_element_factory_make("audioconvert",
		"audio_convert1");
	data.audio_resample = gst_element_factory_make("audioresample",
		"audio_resample");
	data.audio_sink = gst_element_factory_make("autoaudiosink",
		"audio_sink");
	data.app_queue = gst_element_factory_make("queue", "app_queue");
	//data.audio_decode = gst_element_factory_make ("decodebin",
"audio_decode");
	data.audio_convert2 = gst_element_factory_make("audioconvert",
		"audio_convert2");
	data.app_sink = gst_element_factory_make("appsink", "app_sink");



	/* Create the empty pipeline */
	data.pipeline = gst_pipeline_new("test-pipeline");

	if (!data.pipeline || !data.app_source || !data.tee || !data.audio_queue
		|| !data.audio_convert1 ||
		!data.audio_resample || !data.audio_sink || !data.audio_convert2 ||
		!data.app_queue || !data.app_sink) //||!data.audio_decode||
		//!data.app_decode
	{
		g_printerr("Not all elements could be created.\n");
	return -1;
	}


		/* Configure appsrc */
	gst_audio_info_set_format(&info, GST_AUDIO_FORMAT_S16, SAMPLE_RATE,
1,NULL);
	audio_caps = gst_audio_info_to_caps(&info);
	g_object_set(data.app_source, "caps", audio_caps, "format",GST_FORMAT_TIME,
NULL);
	g_signal_connect(data.app_source, "need-data",
G_CALLBACK(start_feed),&data);
	g_signal_connect(data.app_source, "enough-data",
G_CALLBACK(stop_feed),&data);

	/* Configure appsink */
	g_object_set(data.app_sink, "emit-signals", TRUE, "caps", audio_caps,NULL);
	g_signal_connect(data.app_sink, "new-sample",
G_CALLBACK(new_sample),&data);
	gst_caps_unref(audio_caps);
	// g_free (audio_caps_text);

	/* Link all elements that can be automatically linked because they have
	"Always" pads */
	gst_bin_add_many(GST_BIN(data.pipeline), data.app_source, data.tee,
		data.audio_queue, data.audio_convert1, data.audio_resample,
		data.audio_sink, data.app_queue, data.audio_convert2, data.app_sink,
		NULL);//,data.audio_decode,data.app_decode
	if (gst_element_link_many(data.app_source, data.tee, NULL) != TRUE ||
		gst_element_link_many(data.audio_queue, data.audio_convert1,
			data.audio_resample, data.audio_sink, NULL) != TRUE ||
		gst_element_link_many(data.app_queue,
			data.audio_convert2, data.app_sink, NULL) != TRUE)//,data.app_decode		,
data.audio_decode
	{
		g_printerr("Elements could not be linked.\n");
	gst_object_unref(data.pipeline);
	return -1;
	}

		/* Manually link the Tee, which has "Request" pads */
	tee_audio_pad = gst_element_get_request_pad(data.tee, "src_%u");
	g_print("Obtained request pad %s for audio branch.\n", gst_pad_get_name
	(tee_audio_pad));
	queue_audio_pad = gst_element_get_static_pad(data.audio_queue, "sink");
	tee_app_pad = gst_element_get_request_pad(data.tee, "src_%u");
	g_print("Obtained request pad %s for app branch.\n", gst_pad_get_name
	(tee_app_pad));
	queue_app_pad = gst_element_get_static_pad(data.app_queue, "sink");
	if (gst_pad_link(tee_audio_pad, queue_audio_pad) != GST_PAD_LINK_OK ||
		gst_pad_link(tee_app_pad, queue_app_pad) != GST_PAD_LINK_OK) {
		g_printerr("Tee could not be linked\n");
		gst_object_unref(data.pipeline);
		return -1;
	}
	gst_object_unref(queue_audio_pad);
	gst_object_unref(queue_app_pad);

	/* Instruct the bus to emit signals for each received message, and connect
	to the interesting signals */
	bus = gst_element_get_bus(data.pipeline);
	gst_bus_add_signal_watch(bus);
	g_signal_connect(G_OBJECT(bus), "message::error", (GCallback)error_cb,
		&data);
	gst_object_unref(bus);

	/* Start playing the pipeline */
	gst_element_set_state(data.pipeline, GST_STATE_PLAYING);

	/* Create a GLib Main Loop and set it to run */
	data.main_loop = g_main_loop_new(NULL, FALSE);
	g_main_loop_run(data.main_loop);

	/* Release the request pads from the Tee, and unref them */
	gst_element_release_request_pad(data.tee, tee_audio_pad);
	gst_element_release_request_pad(data.tee, tee_app_pad);
	gst_object_unref(tee_audio_pad);
	gst_object_unref(tee_app_pad);

	/* Free resources */
	gst_element_set_state(data.pipeline, GST_STATE_NULL);
	gst_object_unref(data.pipeline);
	return 0;
}







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adi
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