gstreamer/gst-libs/gst/riff/riffparse.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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
/*#define DEBUG_ENABLED */
#include <riff.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;
GST_DEBUG ("gst_riff_parser: offset new buffer 0x%08lx size 0x%08x", off, GST_BUFFER_SIZE(buf));
if (riff->dataleft) {
gulong newsize;
GST_DEBUG ("gst_riff_parser: recovering left data");
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) {
guint32 *words = (guint32 *)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 (GUINT32_FROM_LE (words[0]) != GST_RIFF_TAG_RIFF) {
riff->state = GST_RIFF_ENOTRIFF;
return riff->state;
}
riff->form = GUINT32_FROM_LE (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;
GST_DEBUG ("gst_riff_parser: have incomplete chunk %08x filled", riff->incomplete_chunk_size);
leftover = riff->incomplete_chunk->size - riff->incomplete_chunk_size;
if (leftover <= size) {
GST_DEBUG ("gst_riff_parser: we can fill it from %08x with %08x bytes = %08x",
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 {
GST_DEBUG ("gst_riff_parser: we cannot fill it %08x >= %08lx", 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++;
GST_DEBUG ("gst_riff_parser: next 0x%08x last 0x%08lx offset %08lx",riff->nextlikely, last, off);
/* loop while the next likely chunk header is in this buffer */
while ((riff->nextlikely+12) <= last) {
guint32 *words = (guint32 *)((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);
GST_DEBUG ("gst_riff_parser: next 0x%08x offset 0x%08lx size 0x%08x",riff->nextlikely,
chunk->offset, chunk->size);
if (riff->nextlikely >= chunk->offset+chunk->size) {
GST_DEBUG ("gst_riff_parser: found END LIST");
/* we have the end of the chunk on the stack, remove it */
riff->chunks = g_list_remove(riff->chunks, chunk);
}
else break;
}
GST_DEBUG ("gst_riff_parser: next likely chunk is at offset 0x%08x",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 = GUINT32_FROM_LE (words[0]);
chunk->size = GUINT32_FROM_LE (words[1]);
chunk->data = (gchar *)(words+2);
/* we need word alignment */
/*if (chunk->size & 0x01) chunk->size++; */
chunk->form = GUINT32_FROM_LE (words[2]); /* fill in the form, might not be valid */
if (chunk->id == GST_RIFF_TAG_LIST) {
GST_DEBUG ("found LIST %s", 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 {
GST_DEBUG ("gst_riff_parser: chunk id offset %08x is 0x%08x '" GST_FOURCC_FORMAT "' and is 0x%08x long",
riff->nextlikely, chunk->id, GST_FOURCC_ARGS(chunk->id),
chunk->size);
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);
GST_DEBUG ("make incomplete buffer %08x", 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;
GST_DEBUG ("gst_riff_parser: not enough data next 0x%08x last 0x%08lx %08x %08lx",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;
}
GstRiffChunk *gst_riff_parser_get_chunk(GstRiff *riff, guint32 fourcc)
{
GList *chunk;
g_return_val_if_fail(riff != NULL, NULL);
chunk = riff->chunks;
while (chunk) {
if (((GstRiffChunk *)(chunk->data))->id == fourcc)
return (GstRiffChunk *)(chunk->data);
chunk = g_list_next(chunk);
}
return NULL;
}
guint32 gst_riff_parser_get_nextlikely(GstRiff *riff)
{
g_return_val_if_fail(riff != NULL, 0);
return riff->nextlikely;
}