Play audio from a memory buffer?
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Hi All,
This should almost be an FAQ but it's not in there so here goes: I have a pipeline thus: file-source -> decodebin -> audioresample -> converter -> audio_output Using location (or fd if I change file_source to a fdsrc) I can happily play most audio I throw at it (including mp3s) providing its in a file. What I would like to do is play from a memory location with the mp3 data already in it. I am assuming I would need to use a fakesrc with a callback to get my data into the pipeline - I've tried lots of variations on this and gotten nowhere. Can I just replace the file-source with the fakesrc, load the data and go (if this is possible couple someone provide an example)? Or do I have to worry about queues and caps? If so, can someone provide an example? Will decodebin suffice or will I have to be more specific? Great software by the way, just tricky to use with mp3s (I know why...). Thanks, Brad |
Re: Play audio from a memory buffer?
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On Tue, 2011-01-04 at 04:35 -0800, bcg wrote:
Hi, > This should almost be an FAQ but it's not in there so here goes: > > I have a pipeline thus: > > file-source -> decodebin -> audioresample -> converter -> audio_output > > Using location (or fd if I change file_source to a fdsrc) I can happily play > most audio I throw at it (including mp3s) providing its in a file. What I > would like to do is play from a memory location with the mp3 data already in > it. > > I am assuming I would need to use a fakesrc with a callback to get my data > into the pipeline - I've tried lots of variations on this and gotten > nowhere. > > Can I just replace the file-source with the fakesrc, load the data and go > (if this is possible couple someone provide an example)? Or do I have to > worry about queues and caps? If so, can someone provide an example? Will > decodebin suffice or will I have to be more specific? Use appsrc. Cheers -Tim ------------------------------------------------------------------------------ Learn how Oracle Real Application Clusters (RAC) One Node allows customers to consolidate database storage, standardize their database environment, and, should the need arise, upgrade to a full multi-node Oracle RAC database without downtime or disruption http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gstreamer-devel |
Re: Play audio from a memory buffer?
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Can appsrc be put in that pipeline in place of filesrc without any additional elements?
Cheers, Brad On 5 January 2011 01:55, Tim-Philipp Müller <[hidden email]> wrote:
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In reply to this post by Tim-Philipp Müller-2
Can appsrc be put in that pipeline, in place of filesrc, without any
additional elements? Cheers, Brad On Wed, Jan 5, 2011 at 1:55 AM, Tim-Philipp Müller <[hidden email]> wrote: > On Tue, 2011-01-04 at 04:35 -0800, bcg wrote: > > Hi, > >> This should almost be an FAQ but it's not in there so here goes: >> >> I have a pipeline thus: >> >> file-source -> decodebin -> audioresample -> converter -> audio_output >> >> Using location (or fd if I change file_source to a fdsrc) I can happily play >> most audio I throw at it (including mp3s) providing its in a file. What I >> would like to do is play from a memory location with the mp3 data already in >> it. >> >> I am assuming I would need to use a fakesrc with a callback to get my data >> into the pipeline - I've tried lots of variations on this and gotten >> nowhere. >> >> Can I just replace the file-source with the fakesrc, load the data and go >> (if this is possible couple someone provide an example)? Or do I have to >> worry about queues and caps? If so, can someone provide an example? Will >> decodebin suffice or will I have to be more specific? > > Use appsrc. > > Cheers > -Tim > > > > ------------------------------------------------------------------------------ > Learn how Oracle Real Application Clusters (RAC) One Node allows customers > to consolidate database storage, standardize their database environment, and, > should the need arise, upgrade to a full multi-node Oracle RAC database > without downtime or disruption > http://p.sf.net/sfu/oracle-sfdevnl > _______________________________________________ > gstreamer-devel mailing list > [hidden email] > https://lists.sourceforge.net/lists/listinfo/gstreamer-devel > ------------------------------------------------------------------------------ Learn how Oracle Real Application Clusters (RAC) One Node allows customers to consolidate database storage, standardize their database environment, and, should the need arise, upgrade to a full multi-node Oracle RAC database without downtime or disruption http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gstreamer-devel |
Re: Play audio from a memory buffer?
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It can be put in the pipeline. But you need to pump data into it from your application. Your application would be (sort of) the 'source' and appsrc is like a cheat code to make the following elements think that there is actually a source element in there at the start of the pipeline feeding them gstbuffers.
Try looking up the output format of filesrc element and package your data similarly and feed it to appsrc. Rest will be taken care by the bin/pipeline. Rohit
On Wed, Jan 5, 2011 at 11:34 AM, Brad Goldsmith <[hidden email]> wrote: Can appsrc be put in that pipeline, in place of filesrc, without any ------------------------------------------------------------------------------ Learn how Oracle Real Application Clusters (RAC) One Node allows customers to consolidate database storage, standardize their database environment, and, should the need arise, upgrade to a full multi-node Oracle RAC database without downtime or disruption http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gstreamer-devel |
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The example:
appsrc-stream.c: example for using appsrc in streaming mode. Fits the bill. It loads a file as a memory map but if you shoehorn in your memory location and size at lines: 207 app->length = g_mapped_file_get_length (app->file); 208 app->data = (guint8 *) g_mapped_file_get_contents (app->file); You'll have a working example of what I was after. Cheers, Brad 1 /* GStreamer 2 * 3 * appsrc-stream.c: example for using appsrc in streaming mode. 4 * 5 * Copyright (C) 2008 Wim Taymans <[hidden email]> 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Library General Public 9 * License as published by the Free Software Foundation; either 10 * version 2 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Library General Public License for more details. 16 * 17 * You should have received a copy of the GNU Library General Public 18 * License along with this library; if not, write to the 19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 20 * Boston, MA 02111-1307, USA. 21 */ 22 23 #ifdef HAVE_CONFIG_H 24 #include "config.h" 25 #endif 26 27 #include <gst/gst.h> 28 29 #include <stdio.h> 30 #include <string.h> 31 #include <stdlib.h> 32 33 GST_DEBUG_CATEGORY (appsrc_playbin_debug); 34 #define GST_CAT_DEFAULT appsrc_playbin_debug 35 36 /* 37 * an example application of using appsrc in streaming push mode. We simply push 38 * buffers into appsrc. The size of the buffers we push can be any size we 39 * choose. 40 * 41 * This example is very close to how one would deal with a streaming webserver 42 * that does not support range requests or does not report the total file size. 43 * 44 * Some optimisations are done so that we don't push too much data. We connect 45 * to the need-data and enough-data signals to start/stop sending buffers. 46 * 47 * Appsrc in streaming mode (the default) does not support seeking so we don't 48 * have to handle any seek callbacks. 49 * 50 * Some formats are able to estimate the duration of the media file based on the 51 * file length (mp3, mpeg,..), others report an unknown length (ogg,..). 52 */ 53 typedef struct _App App; 54 55 struct _App 56 { 57 GstElement *playbin; 58 GstElement *appsrc; 59 60 GMainLoop *loop; 61 guint sourceid; 62 63 GMappedFile *file; 64 guint8 *data; 65 gsize length; 66 guint64 offset; 67 }; 68 69 App s_app; 70 71 #define CHUNK_SIZE 4096 72 73 /* This method is called by the idle GSource in the mainloop. We feed CHUNK_SIZE 74 * bytes into appsrc. 75 * The ide handler is added to the mainloop when appsrc requests us to start 76 * sending data (need-data signal) and is removed when appsrc has enough data 77 * (enough-data signal). 78 */ 79 static gboolean 80 read_data (App * app) 81 { 82 GstBuffer *buffer; 83 guint len; 84 GstFlowReturn ret; 85 86 buffer = gst_buffer_new (); 87 88 if (app->offset >= app->length) { 89 /* we are EOS, send end-of-stream and remove the source */ 90 g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret); 91 return FALSE; 92 } 93 94 /* read the next chunk */ 95 len = CHUNK_SIZE; 96 if (app->offset + len > app->length) 97 len = app->length - app->offset; 98 99 GST_BUFFER_DATA (buffer) = app->data + app->offset; 100 GST_BUFFER_SIZE (buffer) = len; 101 102 GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer, 103 app->offset, len); 104 g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret); 105 if (ret != GST_FLOW_OK) { 106 /* some error, stop sending data */ 107 return FALSE; 108 } 109 110 app->offset += len; 111 112 return TRUE; 113 } 114 115 /* This signal callback is called when appsrc needs data, we add an idle handler 116 * to the mainloop to start pushing data into the appsrc */ 117 static void 118 start_feed (GstElement * playbin, guint size, App * app) 119 { 120 if (app->sourceid == 0) { 121 GST_DEBUG ("start feeding"); 122 app->sourceid = g_idle_add ((GSourceFunc) read_data, app); 123 } 124 } 125 126 /* This callback is called when appsrc has enough data and we can stop sending. 127 * We remove the idle handler from the mainloop */ 128 static void 129 stop_feed (GstElement * playbin, App * app) 130 { 131 if (app->sourceid != 0) { 132 GST_DEBUG ("stop feeding"); 133 g_source_remove (app->sourceid); 134 app->sourceid = 0; 135 } 136 } 137 138 /* this callback is called when playbin2 has constructed a source object to read 139 * from. Since we provided the appsrc:// uri to playbin2, this will be the 140 * appsrc that we must handle. We set up some signals to start and stop pushing 141 * data into appsrc */ 142 static void 143 found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app) 144 { 145 /* get a handle to the appsrc */ 146 g_object_get (orig, pspec->name, &app->appsrc, NULL); 147 148 GST_DEBUG ("got appsrc %p", app->appsrc); 149 150 /* we can set the length in appsrc. This allows some elements to estimate the 151 * total duration of the stream. It's a good idea to set the property when you 152 * can but it's not required. */ 153 g_object_set (app->appsrc, "size", app->length, NULL); 154 155 /* configure the appsrc, we will push data into the appsrc from the 156 * mainloop. */ 157 g_signal_connect (app->appsrc, "need-data", G_CALLBACK (start_feed), app); 158 g_signal_connect (app->appsrc, "enough-data", G_CALLBACK (stop_feed), app); 159 } 160 161 static gboolean 162 bus_message (GstBus * bus, GstMessage * message, App * app) 163 { 164 GST_DEBUG ("got message %s", 165 gst_message_type_get_name (GST_MESSAGE_TYPE (message))); 166 167 switch (GST_MESSAGE_TYPE (message)) { 168 case GST_MESSAGE_ERROR: 169 g_error ("received error"); 170 g_main_loop_quit (app->loop); 171 break; 172 case GST_MESSAGE_EOS: 173 g_main_loop_quit (app->loop); 174 break; 175 default: 176 break; 177 } 178 return TRUE; 179 } 180 181 int 182 main (int argc, char *argv[]) 183 { 184 App *app = &s_app; 185 GError *error = NULL; 186 GstBus *bus; 187 188 gst_init (&argc, &argv); 189 190 GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0, 191 "appsrc playbin example"); 192 193 if (argc < 2) { 194 g_print ("usage: %s <filename>\n", argv[0]); 195 return -1; 196 } 197 198 /* try to open the file as an mmapped file */ 199 app->file = g_mapped_file_new (argv[1], FALSE, &error); 200 if (error) { 201 g_print ("failed to open file: %s\n", error->message); 202 g_error_free (error); 203 return -2; 204 } 205 /* get some vitals, this will be used to read data from the mmapped file and 206 * feed it to appsrc. */ 207 app->length = g_mapped_file_get_length (app->file); 208 app->data = (guint8 *) g_mapped_file_get_contents (app->file); 209 app->offset = 0; 210 211 /* create a mainloop to get messages and to handle the idle handler that will 212 * feed data to appsrc. */ 213 app->loop = g_main_loop_new (NULL, TRUE); 214 215 app->playbin = gst_element_factory_make ("playbin2", NULL); 216 g_assert (app->playbin); 217 218 bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin)); 219 220 /* add watch for messages */ 221 gst_bus_add_watch (bus, (GstBusFunc) bus_message, app); 222 223 /* set to read from appsrc */ 224 g_object_set (app->playbin, "uri", "appsrc://", NULL); 225 226 /* get notification when the source is created so that we get a handle to it 227 * and can configure it */ 228 g_signal_connect (app->playbin, "deep-notify::source", 229 (GCallback) found_source, app); 230 231 /* go to playing and wait in a mainloop. */ 232 gst_element_set_state (app->playbin, GST_STATE_PLAYING); 233 234 /* this mainloop is stopped when we receive an error or EOS */ 235 g_main_loop_run (app->loop); 236 237 GST_DEBUG ("stopping"); 238 239 gst_element_set_state (app->playbin, GST_STATE_NULL); 240 241 /* free the file */ 242 g_mapped_file_free (app->file); 243 244 gst_object_unref (bus); 245 g_main_loop_unref (app->loop); 246 247 return 0; 248 } On Wed, Jan 5, 2011 at 5:30 PM, [hidden email] [via GStreamer-devel] <[hidden email]> wrote: > It can be put in the pipeline. But you need to pump data into it from your > application. Your application would be (sort of) the 'source' and appsrc is > like a cheat code to make the following elements think that there is > actually a source element in there at the start of the pipeline feeding them > gstbuffers. > Try looking up the output format of filesrc element and package your data > similarly and feed it to appsrc. Rest will be taken care by the > bin/pipeline. > Rohit > On Wed, Jan 5, 2011 at 11:34 AM, Brad Goldsmith <[hidden email]> wrote: >> >> Can appsrc be put in that pipeline, in place of filesrc, without any >> additional elements? >> >> Cheers, >> Brad >> >> On Wed, Jan 5, 2011 at 1:55 AM, Tim-Philipp Müller <[hidden email]> wrote: >> > On Tue, 2011-01-04 at 04:35 -0800, bcg wrote: >> > >> > Hi, >> > >> >> This should almost be an FAQ but it's not in there so here goes: >> >> >> >> I have a pipeline thus: >> >> >> >> file-source -> decodebin -> audioresample -> converter -> audio_output >> >> >> >> Using location (or fd if I change file_source to a fdsrc) I can happily >> >> play >> >> most audio I throw at it (including mp3s) providing its in a file. What >> >> I >> >> would like to do is play from a memory location with the mp3 data >> >> already in >> >> it. >> >> >> >> I am assuming I would need to use a fakesrc with a callback to get my >> >> data >> >> into the pipeline - I've tried lots of variations on this and gotten >> >> nowhere. >> >> >> >> Can I just replace the file-source with the fakesrc, load the data and >> >> go >> >> (if this is possible couple someone provide an example)? Or do I have >> >> to >> >> worry about queues and caps? If so, can someone provide an example? >> >> Will >> >> decodebin suffice or will I have to be more specific? >> > >> > Use appsrc. >> > >> > Cheers >> > -Tim >> > >> > >> > >> > >> > ------------------------------------------------------------------------------ >> > Learn how Oracle Real Application Clusters (RAC) One Node allows >> > customers >> > to consolidate database storage, standardize their database environment, >> > and, >> > should the need arise, upgrade to a full multi-node Oracle RAC database >> > without downtime or disruption >> > http://p.sf.net/sfu/oracle-sfdevnl >> > _______________________________________________ >> > gstreamer-devel mailing list >> > [hidden email] >> > https://lists.sourceforge.net/lists/listinfo/gstreamer-devel >> > >> >> >> ------------------------------------------------------------------------------ >> Learn how Oracle Real Application Clusters (RAC) One Node allows customers >> to consolidate database storage, standardize their database environment, >> and, >> should the need arise, upgrade to a full multi-node Oracle RAC database >> without downtime or disruption >> http://p.sf.net/sfu/oracle-sfdevnl >> _______________________________________________ >> gstreamer-devel mailing list >> [hidden email] >> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel > > > ------------------------------------------------------------------------------ > Learn how Oracle Real Application Clusters (RAC) One Node allows customers > to consolidate database storage, standardize their database environment, > and, > should the need arise, upgrade to a full multi-node Oracle RAC database > without downtime or disruption > http://p.sf.net/sfu/oracle-sfdevnl > _______________________________________________ > gstreamer-devel mailing list > [hidden email] > https://lists.sourceforge.net/lists/listinfo/gstreamer-devel > > > ________________________________ > View message @ > http://gstreamer-devel.966125.n4.nabble.com/Play-audio-from-a-memory-buffer-tp3173448p3174884.html > To unsubscribe from Play audio from a memory buffer?, click here. |
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