gstreamer/ext/wavpack/gstwavpackcommon.c
2012-11-04 00:07:18 +00:00

268 lines
7.1 KiB
C

/* GStreamer Wavpack plugin
* Copyright (c) 2005 Arwed v. Merkatz <v.merkatz@gmx.net>
* Copyright (c) 1998 - 2005 Conifer Software
* Copyright (c) 2006 Sebastian Dröge <slomo@circular-chaos.org>
*
* gstwavpackcommon.c: common helper functions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstwavpackcommon.h"
#include <string.h>
#include <gst/gst.h>
GST_DEBUG_CATEGORY_EXTERN (wavpack_debug);
#define GST_CAT_DEFAULT wavpack_debug
gboolean
gst_wavpack_read_header (WavpackHeader * header, guint8 * buf)
{
g_memmove (header, buf, sizeof (WavpackHeader));
#ifndef WAVPACK_OLD_API
WavpackLittleEndianToNative (header, (char *) WavpackHeaderFormat);
#else
little_endian_to_native (header, WavpackHeaderFormat);
#endif
return (memcmp (header->ckID, "wvpk", 4) == 0);
}
/* inspired by the original one in wavpack */
gboolean
gst_wavpack_read_metadata (GstWavpackMetadata * wpmd, guint8 * header_data,
guint8 ** p_data)
{
WavpackHeader hdr;
guint8 *end;
gst_wavpack_read_header (&hdr, header_data);
end = header_data + hdr.ckSize + 8;
if (end - *p_data < 2)
return FALSE;
wpmd->id = GST_READ_UINT8 (*p_data);
wpmd->byte_length = 2 * (guint) GST_READ_UINT8 (*p_data + 1);
*p_data += 2;
if ((wpmd->id & ID_LARGE) == ID_LARGE) {
guint extra;
wpmd->id &= ~ID_LARGE;
if (end - *p_data < 2)
return FALSE;
extra = GST_READ_UINT16_LE (*p_data);
wpmd->byte_length += (extra << 9);
*p_data += 2;
}
if ((wpmd->id & ID_ODD_SIZE) == ID_ODD_SIZE) {
wpmd->id &= ~ID_ODD_SIZE;
--wpmd->byte_length;
}
if (wpmd->byte_length > 0) {
if (end - *p_data < wpmd->byte_length + (wpmd->byte_length & 1)) {
wpmd->data = NULL;
return FALSE;
}
wpmd->data = *p_data;
*p_data += wpmd->byte_length + (wpmd->byte_length & 1);
} else {
wpmd->data = NULL;
}
return TRUE;
}
gint
gst_wavpack_get_default_channel_mask (gint nchannels)
{
gint channel_mask = 0;
/* Set the default channel mask for the given number of channels.
* It's the same as for WAVE_FORMAT_EXTENDED:
* http://www.microsoft.com/whdc/device/audio/multichaud.mspx
*/
switch (nchannels) {
case 11:
channel_mask |= 0x00400;
channel_mask |= 0x00200;
case 9:
channel_mask |= 0x00100;
case 8:
channel_mask |= 0x00080;
channel_mask |= 0x00040;
case 6:
channel_mask |= 0x00020;
channel_mask |= 0x00010;
case 4:
channel_mask |= 0x00008;
case 3:
channel_mask |= 0x00004;
case 2:
channel_mask |= 0x00002;
channel_mask |= 0x00001;
break;
case 1:
/* For mono use front center */
channel_mask |= 0x00004;
break;
}
return channel_mask;
}
static const struct
{
const guint32 ms_mask;
const GstAudioChannelPosition gst_pos;
} layout_mapping[] = {
{
0x00001, GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT}, {
0x00002, GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT}, {
0x00004, GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER}, {
0x00008, GST_AUDIO_CHANNEL_POSITION_LFE1}, {
0x00010, GST_AUDIO_CHANNEL_POSITION_REAR_LEFT}, {
0x00020, GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT}, {
0x00040, GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER}, {
0x00080, GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER}, {
0x00100, GST_AUDIO_CHANNEL_POSITION_REAR_CENTER}, {
0x00200, GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT}, {
0x00400, GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT}, {
0x00800, GST_AUDIO_CHANNEL_POSITION_TOP_CENTER}, {
0x01000, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_LEFT}, {
0x02000, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_CENTER}, {
0x04000, GST_AUDIO_CHANNEL_POSITION_TOP_FRONT_RIGHT}, {
0x08000, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_LEFT}, {
0x10000, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_CENTER}, {
0x20000, GST_AUDIO_CHANNEL_POSITION_TOP_REAR_RIGHT}
};
#define MAX_CHANNEL_POSITIONS G_N_ELEMENTS (layout_mapping)
gboolean
gst_wavpack_get_channel_positions (gint num_channels, gint layout,
GstAudioChannelPosition * pos)
{
gint i, p;
if (num_channels == 1 && layout == 0x00004) {
pos[0] = GST_AUDIO_CHANNEL_POSITION_MONO;
return TRUE;
}
p = 0;
for (i = 0; i < MAX_CHANNEL_POSITIONS; ++i) {
if ((layout & layout_mapping[i].ms_mask) != 0) {
if (p >= num_channels) {
GST_WARNING ("More bits set in the channel layout map than there "
"are channels! Broken file");
return FALSE;
}
if (layout_mapping[i].gst_pos == GST_AUDIO_CHANNEL_POSITION_INVALID) {
GST_WARNING ("Unsupported channel position (mask 0x%08x) in channel "
"layout map - ignoring those channels", layout_mapping[i].ms_mask);
/* what to do? just ignore it and let downstream deal with a channel
* layout that has INVALID positions in it for now ... */
}
pos[p] = layout_mapping[i].gst_pos;
++p;
}
}
if (p != num_channels) {
GST_WARNING ("Only %d bits set in the channel layout map, but there are "
"supposed to be %d channels! Broken file", p, num_channels);
return FALSE;
}
return TRUE;
}
GstAudioChannelPosition *
gst_wavpack_get_default_channel_positions (gint nchannels)
{
GstAudioChannelPosition *pos = g_new (GstAudioChannelPosition, nchannels);
gint i;
if (nchannels == 1) {
pos[0] = GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER;
return pos;
}
for (i = 0; i < nchannels; i++)
pos[i] = layout_mapping[i].gst_pos;
return pos;
}
gint
gst_wavpack_get_channel_mask_from_positions (GstAudioChannelPosition * pos,
gint nchannels)
{
gint channel_mask = 0;
gint i, j;
if (nchannels == 1 && pos[0] == GST_AUDIO_CHANNEL_POSITION_MONO) {
channel_mask = 0x00000004;
return channel_mask;
}
/* FIXME: not exactly efficient but otherwise we need an inverse
* mapping table too */
for (i = 0; i < nchannels; i++) {
for (j = 0; j < MAX_CHANNEL_POSITIONS; j++) {
if (pos[i] == layout_mapping[j].gst_pos) {
channel_mask |= layout_mapping[j].ms_mask;
break;
}
}
}
return channel_mask;
}
gboolean
gst_wavpack_set_channel_mapping (GstAudioChannelPosition * pos, gint nchannels,
gint8 * channel_mapping)
{
gint i, j;
gboolean ret = TRUE;
for (i = 0; i < nchannels; i++) {
for (j = 0; j < MAX_CHANNEL_POSITIONS; j++) {
if (pos[i] == layout_mapping[j].gst_pos) {
channel_mapping[i] = j;
ret &= (i == j);
break;
}
}
}
return !ret;
}