gstreamer/libs/riff/gstriffparse.c

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/* Gnome-Streamer
* 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.
*/
//#define DEBUG_ENABLED
#include <gst/gst.h>
#include <gstriff.h>
GstRiff*
gst_riff_parser_new (GstRiffCallback function, gpointer data)
{
GstRiff *riff;
riff = (GstRiff *)g_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;
riff->new_tag_found = function;
riff->callback_data = data;
riff->incomplete_chunk = NULL;
riff->dataleft = NULL;
return riff;
}
gint
gst_riff_parser_next_buffer (GstRiff *riff, GstBuffer *buf, gulong off)
{
gulong last, size;
GstRiffChunk *chunk;
g_return_val_if_fail(riff != NULL, GST_RIFF_EINVAL);
g_return_val_if_fail(buf != NULL, GST_RIFF_EINVAL);
g_return_val_if_fail(GST_BUFFER_DATA(buf) != NULL, GST_RIFF_EINVAL);
size = GST_BUFFER_SIZE(buf);
last = off + size;
DEBUG("gst_riff_parser: offset new buffer 0x%08lx size 0x%08x\n", off, GST_BUFFER_SIZE(buf));
if (riff->dataleft) {
gulong newsize;
DEBUG("gst_riff_parser: recovering left data\n");
newsize = riff->dataleft_size + size;
riff->dataleft = g_realloc(riff->dataleft, newsize);
memcpy(riff->dataleft+riff->dataleft_size, GST_BUFFER_DATA(buf), size);
gst_buffer_unref(buf);
buf = gst_buffer_new();
GST_BUFFER_DATA(buf) = riff->dataleft;
size = GST_BUFFER_SIZE(buf) = newsize;
off -= riff->dataleft_size;
//last -= riff->dataleft_size;
riff->dataleft = NULL;
}
if (off == 0) {
gulong *words = (gulong *)GST_BUFFER_DATA(buf);
// don't even try to parse the head if it's not there FIXME
if (last < 12) {
riff->state = GST_RIFF_ENOTRIFF;
return riff->state;
}
//g_print("testing is 0x%08lx '%s'\n",words[0],gst_riff_id_to_fourcc(words[0]));
/* verify this is a valid RIFF file, first of all */
if (words[0] != GST_RIFF_TAG_RIFF) {
riff->state = GST_RIFF_ENOTRIFF;
return riff->state;
}
riff->form = words[2];
//g_print("form is 0x%08lx '%s'\n",words[2],gst_riff_id_to_fourcc(words[2]));
riff->nextlikely = 12; /* skip 'RIFF', length, and form */
// all OK here
riff->incomplete_chunk = NULL;
}
// if we have an incomplete chunk from the previous buffer
if (riff->incomplete_chunk) {
guint leftover;
DEBUG("gst_riff_parser: have incomplete chunk %08x filled\n", riff->incomplete_chunk_size);
leftover = riff->incomplete_chunk->size - riff->incomplete_chunk_size;
if (leftover <= size) {
DEBUG("gst_riff_parser: we can fill it from %08x with %08x bytes = %08x\n",
riff->incomplete_chunk_size, leftover,
riff->incomplete_chunk_size+leftover);
memcpy(riff->incomplete_chunk->data+riff->incomplete_chunk_size, GST_BUFFER_DATA(buf), leftover);
if (riff->new_tag_found) {
riff->new_tag_found(riff->incomplete_chunk, riff->callback_data);
}
g_free(riff->incomplete_chunk->data);
g_free(riff->incomplete_chunk);
riff->incomplete_chunk = NULL;
}
else {
DEBUG("gst_riff_parser: we cannot fill it %08x >= %08lx\n", leftover, size);
memcpy(riff->incomplete_chunk->data+riff->incomplete_chunk_size, GST_BUFFER_DATA(buf), size);
riff->incomplete_chunk_size += size;
return 0;
}
}
if (riff->nextlikely & 0x01) riff->nextlikely++;
DEBUG("gst_riff_parser: next 0x%08x last 0x%08lx offset %08x\n",riff->nextlikely, last, off);
/* loop while the next likely chunk header is in this buffer */
while ((riff->nextlikely+12) <= last) {
gulong *words = (gulong *)((guchar *)GST_BUFFER_DATA(buf) + riff->nextlikely - off );
// loop over all of the chunks to check which one is finished
while (riff->chunks) {
chunk = g_list_nth_data(riff->chunks, 0);
DEBUG("gst_riff_parser: next 0x%08x offset 0x%08lx size 0x%08x\n",riff->nextlikely,
chunk->offset, chunk->size);
if (riff->nextlikely >= chunk->offset+chunk->size) {
DEBUG("gst_riff_parser: found END LIST\n");
// we have the end of the chunk on the stack, remove it
riff->chunks = g_list_remove(riff->chunks, chunk);
}
else break;
}
DEBUG("gst_riff_parser: next likely chunk is at offset 0x%08x\n",riff->nextlikely);
chunk = (GstRiffChunk *)g_malloc(sizeof(GstRiffChunk));
g_return_val_if_fail(chunk != NULL, GST_RIFF_ENOMEM);
chunk->offset = riff->nextlikely+8; /* point to the actual data */
chunk->id = words[0];
chunk->size = words[1];
chunk->data = (gchar *)(words+2);
// we need word alignment
//if (chunk->size & 0x01) chunk->size++;
chunk->form = words[2]; /* fill in the form, might not be valid */
if (chunk->id == GST_RIFF_TAG_LIST) {
DEBUG("found LIST %s\n", gst_riff_id_to_fourcc(chunk->form));
riff->nextlikely += 12;
// we push the list chunk on our 'stack'
riff->chunks = g_list_prepend(riff->chunks,chunk);
// send the buffer to the listener if we have received a function
if (riff->new_tag_found) {
riff->new_tag_found(chunk, riff->callback_data);
}
}
else {
DEBUG("gst_riff_parser: chunk id offset %08x is 0x%08lx '%s' and is 0x%08lx long\n",
riff->nextlikely, words[0],
gst_riff_id_to_fourcc(words[0]),words[1]);
riff->nextlikely += 8 + chunk->size; /* doesn't include hdr */
// if this buffer is incomplete
if (riff->nextlikely > last) {
guint left = size - (riff->nextlikely - chunk->size - off);
DEBUG("make incomplete buffer %08x\n", left);
chunk->data = g_malloc(chunk->size);
memcpy(chunk->data, (gchar *)(words+2), left);
riff->incomplete_chunk = chunk;
riff->incomplete_chunk_size = left;
}
else {
// send the buffer to the listener if we have received a function
if (riff->new_tag_found) {
riff->new_tag_found(chunk, riff->callback_data);
}
g_free(chunk);
}
if (riff->nextlikely & 0x01) riff->nextlikely++;
//riff->chunks = g_list_prepend(riff->chunks,chunk);
}
}
if ((riff->nextlikely+12) > last && !riff->incomplete_chunk) {
guint left = last - riff->nextlikely;
DEBUG("gst_riff_parser: not enough data next 0x%08x last 0x%08lx %08x %08x\n",riff->nextlikely,
last, left, off);
riff->dataleft = g_malloc(left);
riff->dataleft_size = left;
memcpy(riff->dataleft, GST_BUFFER_DATA(buf)+size-left, left);
return 0;
}
return 0;
}
void
gst_riff_parser_resync (GstRiff *riff, gulong offset)
{
riff->incomplete_chunk = NULL;
riff->dataleft = NULL;
riff->nextlikely = offset;
}