gstreamer/gst/wavparse/gstriff.c

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/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include <gstriff.h>
GstRiff *gst_riff_new() {
GstRiff *riff;
riff = (GstRiff *)malloc(sizeof(GstRiff));
g_return_val_if_fail(riff != NULL, NULL);
riff->form = 0;
riff->chunks = NULL;
riff->state = 0;
riff->curoffset = 0;
riff->nextlikely = 0;
return riff;
}
gint gst_riff_next_buffer(GstRiff *riff,GstBuffer *buf,gulong off) {
gulong last;
GstRiffChunk *chunk;
g_return_val_if_fail(riff != NULL, 0);
g_return_val_if_fail(buf != NULL, 0);
g_return_val_if_fail(GST_BUFFER_DATA(buf) != NULL, 0);
last = off + GST_BUFFER_SIZE(buf);
if (off == 0) {
gulong *words = (gulong *)GST_BUFFER_DATA(buf);
/* verify this is a valid RIFF file, first of all */
if (words[0] != gst_riff_fourcc_to_id("RIFF")) {
riff->state = GST_RIFF_ENOTRIFF;
return riff->state;
}
riff->form = words[2];
/* g_print("form is 0x%08x '%s'\n",words[2],gst_riff_id_to_fourcc(words[2])); */
riff->nextlikely = 12; /* skip 'RIFF', length, and form */
}
/* loop while the next likely chunk header is in this buffer */
while ((riff->nextlikely+8) < last) {
gulong *words = (gulong *)((guchar *)GST_BUFFER_DATA(buf) + riff->nextlikely);
/* g_print("next likely chunk is at offset 0x%08x\n",riff->nextlikely); */
chunk = (GstRiffChunk *)malloc(sizeof(GstRiffChunk));
g_return_val_if_fail(chunk != NULL,0);
chunk->offset = riff->nextlikely+8; /* point to the actual data */
chunk->id = words[0];
chunk->size = words[1];
/* g_print("chunk id is 0x%08x '%s' and is 0x%08x long\n",words[0], */
/* gst_riff_id_to_fourcc(words[0]),words[1]); */
riff->nextlikely += 8 + chunk->size; /* doesn't include hdr */
riff->chunks = g_list_prepend(riff->chunks,chunk);
}
return 0;
}
gulong gst_riff_fourcc_to_id(gchar *fourcc) {
g_return_val_if_fail(fourcc != NULL,0);
return (fourcc[0] << 0) | (fourcc[1] << 8) |
(fourcc[2] << 16) | (fourcc[3] << 24);
}
gchar *gst_riff_id_to_fourcc(gulong id) {
gchar *fourcc = (gchar *)malloc(5);
g_return_val_if_fail(fourcc != NULL, NULL);
fourcc[0] = (id >> 0) & 0xff;
fourcc[1] = (id >> 8) & 0xff;
fourcc[2] = (id >> 16) & 0xff;
fourcc[3] = (id >> 24) & 0xff;
fourcc[4] = 0;
return fourcc;
}
GList *gst_riff_get_chunk_list(GstRiff *riff) {
g_return_val_if_fail(riff != NULL, NULL);
return riff->chunks;
}
GstRiffChunk *gst_riff_get_chunk(GstRiff *riff,gchar *fourcc) {
GList *chunk;
g_return_val_if_fail(riff != NULL, NULL);
g_return_val_if_fail(fourcc != NULL, NULL);
chunk = riff->chunks;
while (chunk) {
if (((GstRiffChunk *)(chunk->data))->id == gst_riff_fourcc_to_id(fourcc))
return (GstRiffChunk *)(chunk->data);
chunk = g_list_next(chunk);
}
return NULL;
}
gulong gst_riff_get_nextlikely(GstRiff *riff) {
g_return_val_if_fail(riff != NULL, 0);
return riff->nextlikely;
}
/*
guchar *hchar = (guchar *)(buf->data);
gulong hlong = *(gulong *)(buf->data);
g_print("header is 0x%08x native, %02x %02x %02x %02x, '%c%c%c%c'\n",
hlong,
hchar[0],hchar[1],hchar[2],hchar[3],
hchar[0],hchar[1],hchar[2],hchar[3]);
g_print("header 0x%08x translates to '%s'\n",hlong,
gst_riff_id_to_fourcc(hlong));
g_print("header 0x%08x trancodes to 0x%08x\n",hlong,
gst_riff_fourcc_to_id(gst_riff_id_to_fourcc(hlong)));
*/