gstreamer/gst/matroska/ebml-read.c
Edgard Lima 789a7b20ac Just make it compile with --disable-gst-debug.
Original commit message from CVS:
Just make it compile with --disable-gst-debug.
2006-02-03 18:07:35 +00:00

804 lines
18 KiB
C

/* GStreamer EBML I/O
* (c) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
*
* ebml-read.c: read EBML data from file/stream
*
* 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 "ebml-read.h"
#include "ebml-ids.h"
GST_DEBUG_CATEGORY_STATIC (ebmlread_debug);
#define GST_CAT_DEFAULT ebmlread_debug
static void gst_ebml_read_class_init (GstEbmlReadClass * klass);
static void gst_ebml_read_init (GstEbmlRead * ebml);
static GstStateChangeReturn gst_ebml_read_change_state (GstElement * element,
GstStateChange transition);
/* convenience functions */
static gboolean gst_ebml_read_peek_bytes (GstEbmlRead * ebml, guint size,
GstBuffer ** p_buf);
static gboolean gst_ebml_read_pull_bytes (GstEbmlRead * ebml, guint size,
GstBuffer ** p_buf);
static GstElementClass *parent_class; /* NULL */
GType
gst_ebml_read_get_type (void)
{
static GType gst_ebml_read_type; /* 0 */
if (!gst_ebml_read_type) {
static const GTypeInfo gst_ebml_read_info = {
sizeof (GstEbmlReadClass),
NULL,
NULL,
(GClassInitFunc) gst_ebml_read_class_init,
NULL,
NULL,
sizeof (GstEbmlRead),
0,
(GInstanceInitFunc) gst_ebml_read_init,
};
gst_ebml_read_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstEbmlRead",
&gst_ebml_read_info, 0);
}
return gst_ebml_read_type;
}
static void
gst_ebml_read_class_init (GstEbmlReadClass * klass)
{
GstElementClass *gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_peek_parent (klass);
GST_DEBUG_CATEGORY_INIT (ebmlread_debug, "ebmlread",
0, "EBML stream helper class");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_ebml_read_change_state);
}
static void
gst_ebml_read_init (GstEbmlRead * ebml)
{
ebml->sinkpad = NULL;
ebml->level = NULL;
}
static GstStateChangeReturn
gst_ebml_read_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret;
GstEbmlRead *ebml = GST_EBML_READ (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
if (!ebml->sinkpad) {
g_return_val_if_reached (GST_STATE_CHANGE_FAILURE);
}
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
{
g_list_foreach (ebml->level, (GFunc) g_free, NULL);
g_list_free (ebml->level);
ebml->level = NULL;
if (ebml->cached_buffer) {
gst_buffer_unref (ebml->cached_buffer);
ebml->cached_buffer = NULL;
}
ebml->offset = 0;
break;
}
default:
break;
}
return ret;
}
/*
* 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 master
* element reading.
*/
static guint
gst_ebml_read_element_level_up (GstEbmlRead * ebml)
{
guint num = 0;
guint64 pos = ebml->offset;
while (ebml->level != NULL) {
GList *last = g_list_last (ebml->level);
GstEbmlLevel *level = last->data;
if (pos >= level->start + level->length) {
ebml->level = g_list_remove (ebml->level, level);
g_free (level);
num++;
} else {
break;
}
}
return num;
}
/*
* Calls pull_range for (offset,size) without advancing our offset
*/
static gboolean
gst_ebml_read_peek_bytes (GstEbmlRead * ebml, guint size, GstBuffer ** p_buf)
{
GstFlowReturn ret;
/* Caching here actually makes much less difference than one would expect.
* We do it mainly to avoid pulling buffers of 1 byte all the time */
if (ebml->cached_buffer) {
guint64 cache_offset = GST_BUFFER_OFFSET (ebml->cached_buffer);
guint cache_size = GST_BUFFER_SIZE (ebml->cached_buffer);
if (cache_offset <= ebml->offset &&
(ebml->offset + size) < (cache_offset + cache_size)) {
*p_buf = gst_buffer_create_sub (ebml->cached_buffer,
ebml->offset - cache_offset, size);
return TRUE;
}
gst_buffer_unref (ebml->cached_buffer);
ebml->cached_buffer = NULL;
}
if (gst_pad_pull_range (ebml->sinkpad, ebml->offset, MAX (size, 64 * 1024),
&ebml->cached_buffer) == GST_FLOW_OK &&
GST_BUFFER_SIZE (ebml->cached_buffer) >= size) {
*p_buf = gst_buffer_create_sub (ebml->cached_buffer, 0, size);
return TRUE;
}
ret = gst_pad_pull_range (ebml->sinkpad, ebml->offset, size, p_buf);
if (ret != GST_FLOW_OK) {
GST_DEBUG ("pull_range returned %d", ret);
return FALSE;
}
if (GST_BUFFER_SIZE (*p_buf) < size) {
GST_WARNING_OBJECT (ebml, "Dropping short buffer at offset %"
G_GUINT64_FORMAT ": wanted %u bytes, got %u bytes", ebml->offset,
size, GST_BUFFER_SIZE (*p_buf));
gst_buffer_unref (*p_buf);
*p_buf = NULL;
return FALSE;
}
return TRUE;
}
/*
* Calls pull_range for (offset,size) and advances our offset by size
*/
static gboolean
gst_ebml_read_pull_bytes (GstEbmlRead * ebml, guint size, GstBuffer ** p_buf)
{
if (!gst_ebml_read_peek_bytes (ebml, size, p_buf))
return FALSE;
ebml->offset += size;
return TRUE;
}
/*
* Read: the element content data ID.
* Return: FALSE on error.
*/
static gboolean
gst_ebml_read_element_id (GstEbmlRead * ebml, guint32 * id, guint * level_up)
{
GstBuffer *buf;
gint len_mask = 0x80, read = 1, n = 1;
guint32 total;
guint8 b;
if (!gst_ebml_read_peek_bytes (ebml, 1, &buf))
return FALSE;
b = GST_READ_UINT8 (GST_BUFFER_DATA (buf));
gst_buffer_unref (buf);
total = (guint32) b;
while (read <= 4 && !(total & len_mask)) {
read++;
len_mask >>= 1;
}
if (read > 4) {
guint64 pos = ebml->offset;
GST_ELEMENT_ERROR (ebml, STREAM, DEMUX, (NULL),
("Invalid EBML ID size tag (0x%x) at position %llu (0x%llx)",
(guint) b, pos, pos));
return FALSE;
}
if (!gst_ebml_read_peek_bytes (ebml, read, &buf))
return FALSE;
while (n < read) {
b = GST_READ_UINT8 (GST_BUFFER_DATA (buf) + n);
total = (total << 8) | b;
++n;
}
*id = total;
/* level */
if (level_up)
*level_up = gst_ebml_read_element_level_up (ebml);
gst_buffer_unref (buf);
ebml->offset += read;
return TRUE;
}
/*
* Read: element content length.
* Return: the number of bytes read or -1 on error.
*/
static gint
gst_ebml_read_element_length (GstEbmlRead * ebml, guint64 * length)
{
GstBuffer *buf;
gint len_mask = 0x80, read = 1, n = 1, num_ffs = 0;
guint64 total;
guint8 b;
if (!gst_ebml_read_peek_bytes (ebml, 1, &buf))
return -1;
b = GST_READ_UINT8 (GST_BUFFER_DATA (buf));
gst_buffer_unref (buf);
total = (guint64) b;
while (read <= 8 && !(total & len_mask)) {
read++;
len_mask >>= 1;
}
if (read > 8) {
guint64 pos = ebml->offset;
GST_ELEMENT_ERROR (ebml, STREAM, DEMUX, (NULL),
("Invalid EBML length size tag (0x%x) at position %llu (0x%llx)",
(guint) b, pos, pos));
return -1;
}
if ((total &= (len_mask - 1)) == len_mask - 1)
num_ffs++;
if (!gst_ebml_read_peek_bytes (ebml, read, &buf))
return -1;
while (n < read) {
guint8 b = GST_READ_UINT8 (GST_BUFFER_DATA (buf) + n);
if (b == 0xff)
num_ffs++;
total = (total << 8) | b;
++n;
}
gst_buffer_unref (buf);
if (read == num_ffs)
*length = G_MAXUINT64;
else
*length = total;
ebml->offset += read;
return read;
}
/*
* Return: the ID of the next element.
* Level_up contains the amount of levels that this
* next element lies higher than the previous one.
*/
gboolean
gst_ebml_peek_id (GstEbmlRead * ebml, guint * level_up, guint32 * id)
{
guint64 off;
g_assert (level_up);
off = ebml->offset; /* save offset */
if (!gst_ebml_read_element_id (ebml, id, level_up))
return FALSE;
ebml->offset = off; /* restore offset */
return TRUE;
}
/*
* Return the length of the stream in bytes
*/
gint64
gst_ebml_read_get_length (GstEbmlRead * ebml)
{
GstFormat fmt = GST_FORMAT_BYTES;
gint64 end;
if (!gst_pad_query_duration (GST_PAD_PEER (ebml->sinkpad), &fmt, &end))
g_return_val_if_reached (0); ///// FIXME /////////
if (fmt != GST_FORMAT_BYTES || end < 0)
g_return_val_if_reached (0); ///// FIXME /////////
return end;
}
/*
* Seek to a given offset.
*/
gboolean
gst_ebml_read_seek (GstEbmlRead * ebml, guint64 offset)
{
if (offset >= gst_ebml_read_get_length (ebml))
return FALSE;
ebml->offset = offset;
return TRUE;
}
/*
* Skip the next element.
*/
gboolean
gst_ebml_read_skip (GstEbmlRead * ebml)
{
guint64 length;
guint32 id;
if (!gst_ebml_read_element_id (ebml, &id, NULL))
return FALSE;
if (gst_ebml_read_element_length (ebml, &length) < 0)
return FALSE;
ebml->offset += length;
return TRUE;
}
/*
* Read the next element as a GstBuffer (binary).
*/
gboolean
gst_ebml_read_buffer (GstEbmlRead * ebml, guint32 * id, GstBuffer ** buf)
{
guint64 length;
if (!gst_ebml_read_element_id (ebml, id, NULL))
return FALSE;
if (gst_ebml_read_element_length (ebml, &length) < 0)
return FALSE;
if (length == 0) {
*buf = gst_buffer_new ();
return TRUE;
}
*buf = NULL;
if (!gst_ebml_read_pull_bytes (ebml, (guint) length, buf))
return FALSE;
return TRUE;
}
/*
* Read the next element as an unsigned int.
*/
gboolean
gst_ebml_read_uint (GstEbmlRead * ebml, guint32 * id, guint64 * num)
{
GstBuffer *buf;
guint8 *data;
guint size;
if (!gst_ebml_read_buffer (ebml, id, &buf))
return FALSE;
data = GST_BUFFER_DATA (buf);
size = GST_BUFFER_SIZE (buf);
if (size < 1 || size > 8) {
GST_ELEMENT_ERROR (ebml, STREAM, DEMUX, (NULL),
("Invalid integer element size %d at position %llu (0x%llu)",
size, GST_BUFFER_OFFSET (buf), GST_BUFFER_OFFSET (buf)));
gst_buffer_unref (buf);
return FALSE;
}
*num = 0;
while (size > 0) {
*num = (*num << 8) | data[GST_BUFFER_SIZE (buf) - size];
size--;
}
gst_buffer_unref (buf);
return TRUE;
}
/*
* Read the next element as a signed int.
*/
gboolean
gst_ebml_read_sint (GstEbmlRead * ebml, guint32 * id, gint64 * num)
{
GstBuffer *buf;
guint8 *data;
guint size, negative = 0, n = 0;
if (!gst_ebml_read_buffer (ebml, id, &buf))
return FALSE;
data = GST_BUFFER_DATA (buf);
size = GST_BUFFER_SIZE (buf);
if (size < 1 || size > 8) {
GST_ELEMENT_ERROR (ebml, STREAM, DEMUX, (NULL),
("Invalid integer element size %d at position %llu (0x%llx)",
size, GST_BUFFER_OFFSET (buf), GST_BUFFER_OFFSET (buf)));
gst_buffer_unref (buf);
return FALSE;
}
if (data[0] & 0x80) {
negative = 1;
data[0] &= ~0x80;
}
*num = 0;
while (n < size) {
*num = (*num << 8) | data[n++];
}
/* make signed */
if (negative) {
*num = *num - (1LL << ((8 * size) - 1));
}
gst_buffer_unref (buf);
return TRUE;
}
/*
* Read the next element as a float.
*/
gboolean
gst_ebml_read_float (GstEbmlRead * ebml, guint32 * id, gdouble * num)
{
GstBuffer *buf;
guint8 *data;
guint size;
if (!gst_ebml_read_buffer (ebml, id, &buf))
return FALSE;
data = GST_BUFFER_DATA (buf);
size = GST_BUFFER_SIZE (buf);
if (size != 4 && size != 8 && size != 10) {
GST_ELEMENT_ERROR (ebml, STREAM, DEMUX, (NULL),
("Invalid float element size %d at position %llu (0x%llx)",
size, GST_BUFFER_OFFSET (buf), GST_BUFFER_OFFSET (buf)));
gst_buffer_unref (buf);
return FALSE;
}
if (size == 10) {
GST_ELEMENT_ERROR (ebml, CORE, NOT_IMPLEMENTED, (NULL),
("FIXME! 10-byte floats unimplemented"));
gst_buffer_unref (buf);
return FALSE;
}
if (size == 4) {
gfloat f;
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
f = *(gfloat *) data;
#else
while (size > 0) {
((guint8 *) & f)[size - 1] = data[4 - size];
size--;
}
#endif
*num = f;
} else {
gdouble d;
#if (G_BYTE_ORDER == G_BIG_ENDIAN)
d = *(gdouble *) data;
#else
while (size > 0) {
((guint8 *) & d)[size - 1] = data[8 - size];
size--;
}
#endif
*num = d;
}
gst_buffer_unref (buf);
return TRUE;
}
/*
* Read the next element as an ASCII string.
*/
gboolean
gst_ebml_read_ascii (GstEbmlRead * ebml, guint32 * id, gchar ** str)
{
GstBuffer *buf;
if (!gst_ebml_read_buffer (ebml, id, &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 the next element as a UTF-8 string.
*/
gboolean
gst_ebml_read_utf8 (GstEbmlRead * ebml, guint32 * id, gchar ** str)
{
gboolean ret;
#ifndef GST_DISABLE_GST_DEBUG
guint64 oldoff = ebml->offset;
#endif
ret = gst_ebml_read_ascii (ebml, id, str);
if (str != NULL && *str != NULL && **str != '\0' &&
!g_utf8_validate (*str, -1, NULL)) {
GST_WARNING ("Invalid UTF-8 string at offset %" G_GUINT64_FORMAT, oldoff);
}
return ret;
}
/*
* Read the next element as a date.
* Returns the seconds since the unix epoch.
*/
gboolean
gst_ebml_read_date (GstEbmlRead * ebml, guint32 * id, gint64 * date)
{
gint64 ebml_date;
gboolean res = gst_ebml_read_sint (ebml, id, &ebml_date);
*date = (ebml_date / GST_SECOND) + GST_EBML_DATE_OFFSET;
return res;
}
/*
* Read the next element, but only the header. The contents
* are supposed to be sub-elements which can be read separately.
*/
gboolean
gst_ebml_read_master (GstEbmlRead * ebml, guint32 * id)
{
GstEbmlLevel *level;
guint64 length;
if (!gst_ebml_read_element_id (ebml, id, NULL))
return FALSE;
if (gst_ebml_read_element_length (ebml, &length) < 0)
return FALSE;
/* remember level */
level = g_new (GstEbmlLevel, 1);
level->start = ebml->offset;
level->length = length;
ebml->level = g_list_append (ebml->level, level);
return TRUE;
}
/*
* Read the next element as binary data.
*/
gboolean
gst_ebml_read_binary (GstEbmlRead * ebml,
guint32 * id, guint8 ** binary, guint64 * length)
{
GstBuffer *buf;
if (!gst_ebml_read_buffer (ebml, id, &buf))
return FALSE;
*length = GST_BUFFER_SIZE (buf);
*binary = g_memdup (GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
gst_buffer_unref (buf);
return TRUE;
}
/*
* Read an EBML header.
*/
gboolean
gst_ebml_read_header (GstEbmlRead * ebml, gchar ** doctype, guint * version)
{
/* this function is the first to be called */
guint32 id;
guint level_up;
/* default init */
if (doctype)
*doctype = NULL;
if (version)
*version = 1;
if (!gst_ebml_peek_id (ebml, &level_up, &id))
return FALSE;
GST_DEBUG_OBJECT (ebml, "id: %08x", GST_READ_UINT32_BE (&id));
if (level_up != 0 || id != GST_EBML_ID_HEADER) {
GST_ELEMENT_ERROR (ebml, STREAM, WRONG_TYPE, (NULL), (NULL));
return FALSE;
}
if (!gst_ebml_read_master (ebml, &id))
return FALSE;
while (TRUE) {
if (!gst_ebml_peek_id (ebml, &level_up, &id))
return FALSE;
/* end-of-header */
if (level_up)
break;
switch (id) {
/* is our read version uptodate? */
case GST_EBML_ID_EBMLREADVERSION:{
guint64 num;
if (!gst_ebml_read_uint (ebml, &id, &num))
return FALSE;
g_assert (id == GST_EBML_ID_EBMLREADVERSION);
if (num != GST_EBML_VERSION)
return FALSE;
break;
}
/* we only handle 8 byte lengths at max */
case GST_EBML_ID_EBMLMAXSIZELENGTH:{
guint64 num;
if (!gst_ebml_read_uint (ebml, &id, &num))
return FALSE;
g_assert (id == GST_EBML_ID_EBMLMAXSIZELENGTH);
if (num != sizeof (guint64))
return FALSE;
break;
}
/* we handle 4 byte IDs at max */
case GST_EBML_ID_EBMLMAXIDLENGTH:{
guint64 num;
if (!gst_ebml_read_uint (ebml, &id, &num))
return FALSE;
g_assert (id == GST_EBML_ID_EBMLMAXIDLENGTH);
if (num != sizeof (guint32))
return FALSE;
break;
}
case GST_EBML_ID_DOCTYPE:{
gchar *text;
if (!gst_ebml_read_ascii (ebml, &id, &text))
return FALSE;
g_assert (id == GST_EBML_ID_DOCTYPE);
if (doctype) {
if (doctype)
g_free (*doctype);
*doctype = text;
} else
g_free (text);
break;
}
case GST_EBML_ID_DOCTYPEREADVERSION:{
guint64 num;
if (!gst_ebml_read_uint (ebml, &id, &num))
return FALSE;
g_assert (id == GST_EBML_ID_DOCTYPEREADVERSION);
if (version)
*version = num;
break;
}
default:
GST_WARNING ("Unknown data type 0x%x in EBML header (ignored)", id);
/* pass-through */
/* we ignore these two, as they don't tell us anything we care about */
case GST_EBML_ID_VOID:
case GST_EBML_ID_EBMLVERSION:
case GST_EBML_ID_DOCTYPEVERSION:
if (!gst_ebml_read_skip (ebml))
return FALSE;
break;
}
}
return TRUE;
}