commit 9c1a32213b9516a18b20cb75ec46bc4eaa9f3fc3
parent eea89183d1fc82745310d8891138806fb090a8cb
Author: Alexander Kojevnikov <alexander@kojevnikov.com>
Date: Fri, 2 Jul 2010 20:01:27 +1000
Average values for decoded audio
Diffstat:
5 files changed, 108 insertions(+), 22 deletions(-)
diff --git a/src/spek-audio.c b/src/spek-audio.c
@@ -55,7 +55,8 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
cx->error = _("The file contains no audio streams");
return cx;
}
- cx->codec_context = cx->format_context->streams[cx->audio_stream]->codec;
+ cx->stream = cx->format_context->streams[cx->audio_stream];
+ cx->codec_context = cx->stream->codec;
cx->codec = avcodec_find_decoder (cx->codec_context->codec_id);
if (cx->codec == NULL) {
cx->error = _("Cannot find decoder");
@@ -71,11 +72,36 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
cx->bits_per_sample = cx->codec_context->bits_per_coded_sample;
}
cx->channels = cx->codec_context->channels;
+ if (cx->channels <= 0) {
+ cx->error = _("No audio channels");
+ return cx;
+ }
cx->buffer_size = (AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2;
if (avcodec_open (cx->codec_context, cx->codec) < 0) {
cx->error = _("Cannot open decoder");
return cx;
}
+ switch (cx->codec_context->sample_fmt) {
+ case SAMPLE_FMT_S16:
+ cx->width = 16;
+ cx->fp = FALSE;
+ break;
+ case SAMPLE_FMT_S32:
+ cx->width = 32;
+ cx->fp = FALSE;
+ break;
+ case SAMPLE_FMT_FLT:
+ cx->width = 32;
+ cx->fp = TRUE;
+ break;
+ case SAMPLE_FMT_DBL:
+ cx->width = 64;
+ cx->fp = TRUE;
+ break;
+ default:
+ cx->error = _("Unsupported sample format");
+ return cx;
+ }
av_init_packet (&cx->packet);
cx->offset = 0;
return cx;
diff --git a/src/spek-audio.h b/src/spek-audio.h
@@ -28,6 +28,7 @@ typedef struct {
AVFormatContext *format_context;
gint audio_stream;
AVCodecContext *codec_context;
+ AVStream *stream;
AVCodec *codec;
AVPacket packet;
gint offset;
@@ -39,6 +40,8 @@ typedef struct {
gint bit_rate;
gint sample_rate;
gint bits_per_sample;
+ gint width; /* number of bits used to store a sample */
+ gboolean fp; /* floating-point sample representation */
gint channels;
gint buffer_size; /* minimum buffer size for spek_audio_read() */
} SpekAudioContext;
diff --git a/src/spek-pipeline.vala b/src/spek-pipeline.vala
@@ -14,15 +14,34 @@
*
* You should have received a copy of the GNU General Public License
* along with Spek. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Conversion of decoded samples into an FFT-happy format is heavily
+ * influenced by GstSpectrum which is part of gst-plugins-good.
+ * The original code:
+ * (c) 1999 Erik Walthinsen <omega@cse.ogi.edu>
+ * (c) 2006 Stefan Kost <ensonic@users.sf.net>
+ * (c) 2007-2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*/
namespace Spek {
public class Pipeline {
- private Audio.Context cx;
public string description { get; private set; }
+ public int sample_rate { get; private set; }
+ public delegate void Callback (int sample, float[] values);
- public Pipeline (string file_name) {
- cx = new Audio.Context (file_name);
+ private Audio.Context cx;
+ private int bands;
+ private int samples;
+ private int threshold;
+ private Callback cb;
+ private uint8[] buffer;
+
+ public Pipeline (string file_name, int bands, int samples, int threshold, Callback cb) {
+ this.cx = new Audio.Context (file_name);
+ this.bands = bands;
+ this.samples = samples;
+ this.threshold = threshold;
+ this.cb = cb;
// Build the description string.
string[] items = {};
@@ -51,24 +70,59 @@ namespace Spek {
description = _("%s: %s").printf (cx.error, description);
}
- var buffer = new uint8[cx.buffer_size];
- while (cx.read (buffer) > 0);
+ this.sample_rate = cx.sample_rate;
+ this.buffer = new uint8[cx.buffer_size];
}
- public string file_name {
- get { return cx.file_name; }
- }
+ public void start () {
+ int nfft = 2 * bands - 2;
+ var input = new float[nfft];
+ int pos = 0;
+ int frames = 0;
+ int size;
+ while ((size = cx.read (this.buffer)) > 0) {
+ uint8 *buffer = (uint8 *) this.buffer;
+ var block_size = cx.width * cx.channels;
+ while (size >= block_size) {
+ input[pos] = average_input (buffer);
+ buffer += block_size;
+ size -= block_size;
+ pos = (pos + 1) % nfft;
+ frames++;
- public int bit_rate {
- get { return cx.bit_rate; }
- }
-
- public int sample_rate {
- get { return cx.sample_rate; }
+ // TODO
+ }
+ assert (size == 0);
+ }
}
- public int channels {
- get { return cx.channels; }
+ private float average_input (uint8 *buffer) {
+ float res = 0f;
+ float max_value = cx.bits_per_sample > 1 ? (1UL << (cx.bits_per_sample - 1)) - 1 : 0;
+ if (cx.fp && cx.width == 32) {
+ float *p = (float *) buffer;
+ for (int i = 0; i < cx.channels; i++) {
+ res += p[i];
+ }
+ } else if (cx.fp && cx.width == 64) {
+ double *p = (double *) buffer;
+ for (int i = 0; i < cx.channels; i++) {
+ res += (float) p[i];
+ }
+ } else if (!cx.fp && cx.width == 32) {
+ int32 *p = (int32 *) buffer;
+ for (int i = 0; i < cx.channels; i++) {
+ res += p[i] / (max_value == 0 ? int32.MAX : max_value);
+ }
+ } else if (!cx.fp && cx.width == 16) {
+ int64 *p = (int64 *) buffer;
+ for (int i = 0; i < cx.channels; i++) {
+ res += p[i] / (max_value == 0 ? int16.MAX : max_value);
+ }
+ } else {
+ assert_not_reached ();
+ }
+ return res / cx.channels;
}
}
}
diff --git a/src/spek-spectrogram.vala b/src/spek-spectrogram.vala
@@ -63,10 +63,6 @@ namespace Spek {
this.file_name = file_name;
this.info = "";
- // TODO
- var pipeline = new Pipeline (file_name);
- print ("\n%s:\n%s\n", file_name, pipeline.description);
-
start ();
}
@@ -92,6 +88,11 @@ namespace Spek {
image = null;
source = null;
}
+
+ // TODO
+ var pipeline = new Pipeline (file_name, BANDS, samples, THRESHOLD, data_cb);
+ print ("\n%s:\n%s\n", file_name, pipeline.description);
+
queue_draw ();
}
@@ -240,7 +241,7 @@ namespace Spek {
unowned uchar[] data = surface.get_data ();
// Translate uchar* to uint32* to avoid dealing with endianness.
- uint32 *p = &data[i];
+ uint32 *p = (uint32 *) (&data[i]);
*p = color;
}
diff --git a/vapi/spek-audio.vapi b/vapi/spek-audio.vapi
@@ -9,6 +9,8 @@ namespace Spek.Audio {
public int bit_rate;
public int sample_rate;
public int bits_per_sample;
+ public int width;
+ public bool fp;
public int channels;
public int buffer_size;
