gstreamer/gst-libs/gst/riff/riff-read.c

870 lines
22 KiB
C
Raw Normal View History

/* GStreamer RIFF I/O
* Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
*
* riff-read.c: RIFF input file parsing
*
* 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>
#include "riff-ids.h"
#include "riff-read.h"
enum {
ARG_0,
ARG_METADATA
/* FILL ME */
};
static void gst_riff_read_class_init (GstRiffReadClass *klass);
static void gst_riff_read_init (GstRiffRead *riff);
static void gst_riff_read_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static GstElementStateReturn
gst_riff_read_change_state (GstElement *element);
static GstElementClass *parent_class = NULL;
GType
gst_riff_read_get_type (void)
{
static GType gst_riff_read_type = 0;
if (!gst_riff_read_type) {
static const GTypeInfo gst_riff_read_info = {
sizeof (GstRiffReadClass),
NULL,
NULL,
(GClassInitFunc) gst_riff_read_class_init,
NULL,
NULL,
sizeof (GstRiffRead),
0,
(GInstanceInitFunc) gst_riff_read_init,
};
gst_riff_read_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstRiffRead",
&gst_riff_read_info, 0);
}
return gst_riff_read_type;
}
static void
gst_riff_read_class_init (GstRiffReadClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
g_object_class_install_property (gobject_class, ARG_METADATA,
g_param_spec_boxed ("metadata", "Metadata", "Metadata",
GST_TYPE_CAPS, G_PARAM_READABLE));
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
gobject_class->get_property = gst_riff_read_get_property;
gstelement_class->change_state = gst_riff_read_change_state;
}
static void
gst_riff_read_init (GstRiffRead *riff)
{
riff->sinkpad = NULL;
riff->bs = NULL;
riff->level = NULL;
riff->metadata = NULL;
}
static void
gst_riff_read_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GstRiffRead *riff = GST_RIFF_READ (object);
switch (prop_id) {
case ARG_METADATA:
g_value_set_boxed (value, riff->metadata);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstElementStateReturn
gst_riff_read_change_state (GstElement *element)
{
GstRiffRead *riff = GST_RIFF_READ (element);
switch (GST_STATE_TRANSITION (element)) {
case GST_STATE_READY_TO_PAUSED:
if (!riff->sinkpad)
return GST_STATE_FAILURE;
riff->bs = gst_bytestream_new (riff->sinkpad);
break;
case GST_STATE_PAUSED_TO_READY:
gst_caps_replace (&riff->metadata, NULL);
gst_bytestream_destroy (riff->bs);
while (riff->level) {
GstRiffLevel *level = riff->level->data;
riff->level = g_list_remove (riff->level, level);
g_free (level);
}
break;
default:
break;
}
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return GST_ELEMENT_CLASS (parent_class)->change_state (element);
return GST_STATE_SUCCESS;
}
/*
* Return: the amount of levels in the hierarchy that the
* current element lies higher than the previous one.
* The opposite isn't done - that's auto-done using list
* element reading.
*/
static guint
gst_riff_read_element_level_up (GstRiffRead *riff)
{
guint num = 0;
guint64 pos = gst_bytestream_tell (riff->bs);
while (riff->level != NULL) {
GList *last = g_list_last (riff->level);
GstRiffLevel *level = last->data;
if (pos >= level->start + level->length) {
riff->level = g_list_remove (riff->level, level);
g_free (level);
num++;
} else
break;
}
return num;
}
/*
* Read the next tag plus length (may be NULL). Return
* TRUE on success or FALSE on failure.
*/
static gboolean
gst_riff_peek_head (GstRiffRead *riff,
guint32 *tag,
guint32 *length,
guint *level_up)
{
guint8 *data;
/* read */
if (gst_bytestream_peek_bytes (riff->bs, &data, 8) != 8) {
GstEvent *event = NULL;
guint32 remaining;
/* Here, we might encounter EOS */
gst_bytestream_get_status (riff->bs, &remaining, &event);
if (event && GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
gst_pad_event_default (riff->sinkpad, event);
} else {
gst_event_unref (event);
gst_element_error (GST_ELEMENT (riff), "Read error");
}
return FALSE;
}
/* parse tag + length (if wanted) */
*tag = GUINT32_FROM_LE (((guint32 *) data)[0]);
if (length)
*length = GUINT32_FROM_LE (((guint32 *) data)[1]);
/* level */
if (level_up)
*level_up = gst_riff_read_element_level_up (riff);
return TRUE;
}
/*
* Read: the actual data (plus alignment and flush).
* Return: the data, as a GstBuffer.
*/
static GstBuffer *
gst_riff_read_element_data (GstRiffRead *riff,
guint length)
{
GstBuffer *buf = NULL;
if (gst_bytestream_peek (riff->bs, &buf, length) != length) {
gst_element_error (GST_ELEMENT (riff), "Read error");
if (buf)
gst_buffer_unref (buf);
return NULL;
}
/* we need 16-bit alignment */
if (length & 1)
length++;
gst_bytestream_flush (riff->bs, length);
return buf;
}
/*
* Seek.
*/
GstEvent *
gst_riff_read_seek (GstRiffRead *riff,
guint64 offset)
{
guint64 length = gst_bytestream_length (riff->bs);
guint32 remaining;
GstEvent *event;
guchar *data;
/* hack for AVI files with broken idx1 size chunk markers */
if (offset > length)
offset = length;
/* first, flush remaining buffers */
gst_bytestream_get_status (riff->bs, &remaining, &event);
if (event) {
g_warning ("Unexpected event before seek");
gst_event_unref (event);
}
if (remaining)
gst_bytestream_flush_fast (riff->bs, remaining);
/* now seek */
if (!gst_bytestream_seek (riff->bs, offset, GST_SEEK_METHOD_SET)) {
gst_element_error (GST_ELEMENT (riff), "Seek failed");
return NULL;
}
/* and now, peek a new byte. This will fail because there's a
* pending event. Then, take the event and return it. */
if (gst_bytestream_peek_bytes (riff->bs, &data, 1))
g_warning ("Unexpected data after seek");
/* get the discont event and return */
gst_bytestream_get_status (riff->bs, &remaining, &event);
if (!event || GST_EVENT_TYPE (event) != GST_EVENT_DISCONTINUOUS) {
gst_element_error (GST_ELEMENT (riff),
"No discontinuity event after seek");
if (event)
gst_event_unref (event);
return NULL;
}
return event;
}
/*
* Gives the tag of the next RIFF element.
*/
guint32
gst_riff_peek_tag (GstRiffRead *riff,
guint *level_up)
{
guint32 tag;
if (!gst_riff_peek_head (riff, &tag, NULL, level_up))
return 0;
return tag;
}
/*
* Gives the tag of the next LIST/RIFF element.
*/
guint32
gst_riff_peek_list (GstRiffRead *riff)
{
guint32 lst;
guint8 *data;
if (!gst_riff_peek_head (riff, &lst, NULL, NULL))
return FALSE;
if (lst != GST_RIFF_TAG_LIST) {
g_warning ("Not a LIST object");
return 0;
}
if (gst_bytestream_peek_bytes (riff->bs, &data, 12) != 12) {
gst_element_error (GST_ELEMENT (riff), "Read error");
return 0;
}
return GUINT32_FROM_LE (((guint32 *) data)[2]);
}
/*
* Don't read data.
*/
gboolean
gst_riff_read_skip (GstRiffRead *riff)
{
guint32 tag, length;
GstEvent *event;
guint32 remaining;
if (!gst_riff_peek_head (riff, &tag, &length, NULL))
return FALSE;
/* 16-bit alignment */
if (length & 1)
length++;
/* header itself */
length += 8;
/* see if we have that much data available */
gst_bytestream_get_status (riff->bs, &remaining, &event);
if (event) {
g_warning ("Unexpected event in skip");
gst_event_unref (event);
}
/* yes */
if (remaining >= length) {
gst_bytestream_flush_fast (riff->bs, length);
return TRUE;
}
/* no */
if (!(event = gst_riff_read_seek (riff,
gst_bytestream_tell (riff->bs) + length)))
return FALSE;
gst_event_unref (event);
return TRUE;
}
/*
* Read any type of data.
*/
gboolean
gst_riff_read_data (GstRiffRead *riff,
guint32 *tag,
GstBuffer **buf)
{
guint32 length;
if (!gst_riff_peek_head (riff, tag, &length, NULL))
return FALSE;
gst_bytestream_flush_fast (riff->bs, 8);
return ((*buf = gst_riff_read_element_data (riff, length)) != NULL);
}
/*
* Read a string.
*/
gboolean
gst_riff_read_ascii (GstRiffRead *riff,
guint32 *tag,
gchar **str)
{
GstBuffer *buf;
if (!gst_riff_read_data (riff, tag, &buf))
return FALSE;
*str = g_malloc (GST_BUFFER_SIZE (buf) + 1);
memcpy (*str, GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
(*str)[GST_BUFFER_SIZE (buf)] = '\0';
gst_buffer_unref (buf);
return TRUE;
}
/*
* Read media structs.
*/
gboolean
gst_riff_read_strh (GstRiffRead *riff,
gst_riff_strh **header)
{
guint32 tag;
GstBuffer *buf;
gst_riff_strh *strh;
if (!gst_riff_read_data (riff, &tag, &buf))
return FALSE;
if (tag != GST_RIFF_TAG_strh) {
g_warning ("Not a strh chunk");
gst_buffer_unref (buf);
return FALSE;
}
if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_strh)) {
g_warning ("Too small strh (%d available, %d needed)",
GST_BUFFER_SIZE (buf), sizeof (gst_riff_strh));
gst_buffer_unref (buf);
return FALSE;
}
strh = g_memdup (GST_BUFFER_DATA (buf),
GST_BUFFER_SIZE (buf));
gst_buffer_unref (buf);
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
strh->type = GUINT32_FROM_LE (strh->type);
strh->fcc_handler = GUINT32_FROM_LE (strh->fcc_handler);
strh->flags = GUINT32_FROM_LE (strh->flags);
strh->priority = GUINT32_FROM_LE (strh->priority);
strh->init_frames = GUINT32_FROM_LE (strh->init_frames);
strh->scale = GUINT32_FROM_LE (strh->scale);
strh->rate = GUINT32_FROM_LE (strh->rate);
strh->start = GUINT32_FROM_LE (strh->start);
strh->length = GUINT32_FROM_LE (strh->length);
strh->bufsize = GUINT32_FROM_LE (strh->bufsize);
strh->quality = GUINT32_FROM_LE (strh->quality);
strh->samplesize = GUINT32_FROM_LE (strh->samplesize);
#endif
/* avoid divisions by zero */
if (!strh->scale)
strh->scale = 1;
if (!strh->rate)
strh->rate = 1;
/* debug */
GST_INFO ("strh tag found");
GST_INFO (" type " GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (strh->type));
GST_INFO (" fcc_handler " GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (strh->fcc_handler));
GST_INFO (" flags 0x%08x", strh->flags);
GST_INFO (" priority %d", strh->priority);
GST_INFO (" init_frames %d", strh->init_frames);
GST_INFO (" scale %d", strh->scale);
GST_INFO (" rate %d", strh->rate);
GST_INFO (" start %d", strh->start);
GST_INFO (" length %d", strh->length);
GST_INFO (" bufsize %d", strh->bufsize);
GST_INFO (" quality %d", strh->quality);
GST_INFO (" samplesize %d", strh->samplesize);
*header = strh;
return TRUE;
}
gboolean
gst_riff_read_strf_vids (GstRiffRead *riff,
gst_riff_strf_vids **header)
{
guint32 tag;
GstBuffer *buf;
gst_riff_strf_vids *strf;
if (!gst_riff_read_data (riff, &tag, &buf))
return FALSE;
if (tag != GST_RIFF_TAG_strf) {
g_warning ("Not a strf chunk");
gst_buffer_unref (buf);
return FALSE;
}
if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_strf_vids)) {
g_warning ("Too small strf_vids (%d available, %d needed)",
GST_BUFFER_SIZE (buf), sizeof (gst_riff_strf_vids));
gst_buffer_unref (buf);
return FALSE;
}
strf = g_memdup (GST_BUFFER_DATA (buf),
GST_BUFFER_SIZE (buf));
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
strf->size = GUINT32_FROM_LE (strf->size);
strf->width = GUINT32_FROM_LE (strf->width);
strf->height = GUINT32_FROM_LE (strf->height);
strf->planes = GUINT16_FROM_LE (strf->planes);
strf->bit_cnt = GUINT16_FROM_LE (strf->bit_cnt);
strf->compression = GUINT32_FROM_LE (strf->compression);
strf->image_size = GUINT32_FROM_LE (strf->image_size);
strf->xpels_meter = GUINT32_FROM_LE (strf->xpels_meter);
strf->ypels_meter = GUINT32_FROM_LE (strf->ypels_meter);
strf->num_colors = GUINT32_FROM_LE (strf->num_colors);
strf->imp_colors = GUINT32_FROM_LE (strf->imp_colors);
#endif
/* size checking */
if (strf->size > GST_BUFFER_SIZE (buf)) {
g_warning ("strf_vids header gave %d bytes data, only %d available",
strf->size, GST_BUFFER_SIZE (buf));
strf->size = GST_BUFFER_SIZE (buf);
}
/* debug */
GST_INFO ("strf tag found in context vids:");
GST_INFO (" size %d", strf->size);
GST_INFO (" width %d", strf->width);
GST_INFO (" height %d", strf->height);
GST_INFO (" planes %d", strf->planes);
GST_INFO (" bit_cnt %d", strf->bit_cnt);
GST_INFO (" compression " GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (strf->compression));
GST_INFO (" image_size %d", strf->image_size);
GST_INFO (" xpels_meter %d", strf->xpels_meter);
GST_INFO (" ypels_meter %d", strf->ypels_meter);
GST_INFO (" num_colors %d", strf->num_colors);
GST_INFO (" imp_colors %d", strf->imp_colors);
gst_buffer_unref (buf);
*header = strf;
return TRUE;
}
gboolean
gst_riff_read_strf_auds (GstRiffRead *riff,
gst_riff_strf_auds **header)
{
guint32 tag;
GstBuffer *buf;
gst_riff_strf_auds *strf;
if (!gst_riff_read_data (riff, &tag, &buf))
return FALSE;
if (tag != GST_RIFF_TAG_strf) {
g_warning ("Not a strf chunk");
gst_buffer_unref (buf);
return FALSE;
}
if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_strf_auds)) {
g_warning ("Too small strf_auds (%d available, %d needed)",
GST_BUFFER_SIZE (buf), sizeof (gst_riff_strf_auds));
gst_buffer_unref (buf);
return FALSE;
}
strf = g_memdup (GST_BUFFER_DATA (buf),
GST_BUFFER_SIZE (buf));
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
strf->format = GUINT16_FROM_LE (strf->format);
strf->channels = GUINT16_FROM_LE (strf->channels);
strf->rate = GUINT32_FROM_LE (strf->rate);
strf->av_bps = GUINT32_FROM_LE (strf->av_bps);
strf->blockalign = GUINT16_FROM_LE (strf->blockalign);
strf->size = GUINT16_FROM_LE (strf->size);
#endif
/* debug */
GST_INFO ("strf tag found in context auds:");
GST_INFO (" format %d", strf->format);
GST_INFO (" channels %d", strf->channels);
GST_INFO (" rate %d", strf->rate);
GST_INFO (" av_bps %d", strf->av_bps);
GST_INFO (" blockalign %d", strf->blockalign);
GST_INFO (" size %d", strf->size); /* wordsize, not extrasize! */
gst_buffer_unref (buf);
*header = strf;
return TRUE;
}
gboolean
gst_riff_read_strf_iavs (GstRiffRead *riff,
gst_riff_strf_iavs **header)
{
guint32 tag;
GstBuffer *buf;
gst_riff_strf_iavs *strf;
if (!gst_riff_read_data (riff, &tag, &buf))
return FALSE;
if (tag != GST_RIFF_TAG_strf) {
g_warning ("Not a strf chunk");
gst_buffer_unref (buf);
return FALSE;
}
if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_strf_iavs)) {
g_warning ("Too small strf_iavs (%d available, %d needed)",
GST_BUFFER_SIZE (buf), sizeof (gst_riff_strf_iavs));
gst_buffer_unref (buf);
return FALSE;
}
strf = g_memdup (GST_BUFFER_DATA (buf),
GST_BUFFER_SIZE (buf));
gst_buffer_unref (buf);
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
strf->DVAAuxSrc = GUINT32_FROM_LE (strf->DVAAuxSrc);
strf->DVAAuxCtl = GUINT32_FROM_LE (strf->DVAAuxCtl);
strf->DVAAuxSrc1 = GUINT32_FROM_LE (strf->DVAAuxSrc1);
strf->DVAAuxCtl1 = GUINT32_FROM_LE (strf->DVAAuxCtl1);
strf->DVVAuxSrc = GUINT32_FROM_LE (strf->DVVAuxSrc);
strf->DVVAuxCtl = GUINT32_FROM_LE (strf->DVVAuxCtl);
strf->DVReserved1 = GUINT32_FROM_LE (strf->DVReserved1);
strf->DVReserved2 = GUINT32_FROM_LE (strf->DVReserved2);
#endif
/* debug */
GST_INFO ("strf tag found in context iavs");
GST_INFO (" DVAAuxSrc %08x", strf->DVAAuxSrc);
GST_INFO (" DVAAuxCtl %08x", strf->DVAAuxCtl);
GST_INFO (" DVAAuxSrc1 %08x", strf->DVAAuxSrc1);
GST_INFO (" DVAAuxCtl1 %08x", strf->DVAAuxCtl1);
GST_INFO (" DVVAuxSrc %08x", strf->DVVAuxSrc);
GST_INFO (" DVVAuxCtl %08x", strf->DVVAuxCtl);
GST_INFO (" DVReserved1 %08x", strf->DVReserved1);
GST_INFO (" DVReserved2 %08x", strf->DVReserved2);
*header = strf;
return TRUE;
}
/*
* Read a list.
*/
gboolean
gst_riff_read_list (GstRiffRead *riff,
guint32 *tag)
{
guint32 length, lst;
GstRiffLevel *level;
guint8 *data;
if (!gst_riff_peek_head (riff, &lst, &length, NULL))
return FALSE;
if (lst != GST_RIFF_TAG_LIST) {
g_warning ("Not a LIST object");
return FALSE;
}
gst_bytestream_flush_fast (riff->bs, 8);
if (gst_bytestream_peek_bytes (riff->bs, &data, 4) != 4) {
gst_element_error (GST_ELEMENT (riff), "Read error");
return FALSE;
}
gst_bytestream_flush_fast (riff->bs, 4);
*tag = GUINT32_FROM_LE (* (guint32 *) data);
/* remember level */
level = g_new (GstRiffLevel, 1);
level->start = gst_bytestream_tell (riff->bs);
level->length = length - 4;
riff->level = g_list_append (riff->level, level);
return TRUE;
}
/*
* Utility function for reading metadata in a RIFF file.
*/
gboolean
gst_riff_read_info (GstRiffRead *riff)
{
guint32 tag;
guint64 end;
GstRiffLevel *level;
GList *last;
gchar *name, *type;
GstCaps *caps;
/* What we're doing here is ugly (oh no!); we look
* at our LIST tag size and assure that we do not
* cross boundaries. This is to maintain the level
* counter for the client app. */
last = g_list_last (riff->level);
level = last->data;
riff->level = g_list_remove (riff->level, level);
end = level->start + level->length;
g_free (level);
caps = gst_caps_new_simple ("application/x-gst-metadata", NULL);
while (gst_bytestream_tell (riff->bs) < end) {
if (!gst_riff_peek_head (riff, &tag, NULL, NULL)) {
return FALSE;
}
/* find out the type of metadata */
switch (tag) {
case GST_RIFF_INFO_IARL:
type = "Location";
break;
case GST_RIFF_INFO_IART:
type = "Artist";
break;
case GST_RIFF_INFO_ICMS:
type = "Commissioner";
break;
case GST_RIFF_INFO_ICMT:
type = "Comment";
break;
case GST_RIFF_INFO_ICOP:
type = "Copyright";
break;
case GST_RIFF_INFO_ICRD:
type = "Creation Date";
break;
case GST_RIFF_INFO_ICRP:
type = "Cropped";
break;
case GST_RIFF_INFO_IDIM:
type = "Dimensions";
break;
case GST_RIFF_INFO_IDPI:
type = "Dots per Inch";
break;
case GST_RIFF_INFO_IENG:
type = "Engineer";
break;
case GST_RIFF_INFO_IGNR:
type = "Genre";
break;
case GST_RIFF_INFO_IKEY:
type = "Keywords";
break;
case GST_RIFF_INFO_ILGT:
type = "Lightness";
break;
case GST_RIFF_INFO_IMED:
type = "Medium";
break;
case GST_RIFF_INFO_INAM:
type = "Title"; /* "Name" */
break;
case GST_RIFF_INFO_IPLT:
type = "Palette";
break;
case GST_RIFF_INFO_IPRD:
type = "Product";
break;
case GST_RIFF_INFO_ISBJ:
type = "Subject";
break;
case GST_RIFF_INFO_ISFT:
type = "Encoder"; /* "Software" */
break;
case GST_RIFF_INFO_ISHP:
type = "Sharpness";
break;
case GST_RIFF_INFO_ISRC:
type = "Source";
break;
case GST_RIFF_INFO_ISRF:
type = "Source Form";
break;
case GST_RIFF_INFO_ITCH:
type = "Technician";
break;
default:
type = NULL;
GST_WARNING ("Unknown INFO (metadata) tag entry " GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (tag));
break;
}
if (type) {
if (!gst_riff_read_ascii (riff, &tag, &name)) {
return FALSE;
}
gst_caps_set_simple (caps, type, G_TYPE_STRING, name, NULL);
} else {
gst_riff_read_skip (riff);
}
}
/* let the world know about this wonderful thing */
gst_caps_replace (&riff->metadata, caps);
g_object_notify (G_OBJECT (riff), "metadata");
return TRUE;
}
/*
* Read RIFF header and document type.
*/
gboolean
gst_riff_read_header (GstRiffRead *riff,
guint32 *doctype)
{
GstRiffLevel *level;
guint32 tag, length;
guint8 *data;
/* We ignore size for openDML-2.0 support */
if (!gst_riff_peek_head (riff, &tag, &length, NULL))
return FALSE;
if (tag != GST_RIFF_TAG_RIFF) {
gst_element_error (GST_ELEMENT (riff),
"Not a RIFF file");
return FALSE;
}
gst_bytestream_flush_fast (riff->bs, 8);
/* doctype */
if (gst_bytestream_peek_bytes (riff->bs, &data, 4) != 4) {
gst_element_error (GST_ELEMENT (riff), "Read error");
return FALSE;
}
gst_bytestream_flush_fast (riff->bs, 4);
*doctype = GUINT32_FROM_LE (* (guint32 *) data);
/* remember level */
level = g_new (GstRiffLevel, 1);
level->start = gst_bytestream_tell (riff->bs);
level->length = length - 4;
riff->level = g_list_append (riff->level, level);
return TRUE;
}