blob: 65a43abda29ef308cf41500275333305ce4fbf20 [file] [log] [blame]
/* dvb-sub.c - DVB subtitle decoding
* Copyright (C) Mart Raudsepp 2009 <mart.raudsepp@artecdesign.ee>
* Copyright (C) 2010 ONELAN Ltd.
*
* Heavily uses code algorithms ported from ffmpeg's libavcodec/dvbsubdec.c,
* especially the segment parsers. The original license applies to this
* ported code and the whole code in this file as well.
*
* Original copyright information follows:
*/
/*
* DVB subtitle decoding for ffmpeg
* Copyright (c) 2005 Ian Caulfield
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <string.h> /* memset */
#include <gst/gstutils.h> /* GST_READ_UINT16_BE */
#include <gst/base/gstbitreader.h> /* GstBitReader */
#include "dvb-sub.h"
GST_DEBUG_CATEGORY_STATIC (dvbsub_debug);
#define GST_CAT_DEFAULT dvbsub_debug
static void dvb_sub_init (void);
/* FIXME: Are we waiting for an acquisition point before trying to do things? */
/* FIXME: In the end convert some of the guint8/16 (especially stack variables) back to gint for access efficiency */
/**
* SECTION:dvb-sub
* @short_description: a DVB subtitle parsing class
* @stability: Unstable
*
* The #DvbSub represents an object used for parsing a DVB subpicture,
* and signalling the API user for new bitmaps to show on screen.
*/
#define AYUV(y,u,v,a) (((a) << 24) | ((y) << 16) | ((u) << 8) | (v))
#define RGBA_TO_AYUV(r,g,b,a) (((a) << 24) | ((rgb_to_y(r,g,b)) << 16) | ((rgb_to_u(r,g,b)) << 8) | (rgb_to_v(r,g,b)))
typedef struct DVBSubCLUT
{
int id; /* default_clut uses -1 for this, so guint8 isn't fine without adaptations first */
guint32 clut4[4];
guint32 clut16[16];
guint32 clut256[256];
struct DVBSubCLUT *next;
} DVBSubCLUT;
static DVBSubCLUT default_clut;
typedef struct DVBSubObjectDisplay
{
/* FIXME: Use more correct sizes */
int object_id;
int region_id;
int x_pos;
int y_pos;
int fgcolor;
int bgcolor;
/* FIXME: Should we use GSList? The relating interaction and pointer assigment is quite complex and perhaps unsuited for a plain GSList anyway */
struct DVBSubObjectDisplay *region_list_next;
struct DVBSubObjectDisplay *object_list_next;
} DVBSubObjectDisplay;
typedef struct DVBSubObject
{
/* FIXME: Use more correct sizes */
int id; /* FIXME: Use guint8 after checking it's fine in all code using it */
int type;
/* FIXME: Should we use GSList? */
DVBSubObjectDisplay *display_list;
struct DVBSubObject *next;
} DVBSubObject;
typedef struct DVBSubRegionDisplay
{ /* FIXME: Figure out if this structure is only used temporarily in page_segment parser, or also more */
int region_id;
int x_pos;
int y_pos;
struct DVBSubRegionDisplay *next;
} DVBSubRegionDisplay;
typedef struct DVBSubRegion
{
guint8 id;
guint16 width;
guint16 height;
guint8 depth; /* If we want to make this a guint8, then need to ensure it isn't wrap around with reserved values in region handling code */
guint8 clut;
guint8 bgcolor;
/* FIXME: Validate these fields existence and exact types */
guint8 *pbuf;
int buf_size;
DVBSubObjectDisplay *display_list;
struct DVBSubRegion *next;
} DVBSubRegion;
struct _DvbSub
{
DvbSubCallbacks callbacks;
gpointer user_data;
guint8 page_time_out;
DVBSubRegion *region_list;
DVBSubCLUT *clut_list;
DVBSubObject *object_list;
/* FIXME... */
int display_list_size;
DVBSubRegionDisplay *display_list;
GString *pes_buffer;
DVBSubtitleWindow display_def;
};
typedef enum
{
TOP_FIELD = 0,
BOTTOM_FIELD = 1
} DvbSubPixelDataSubBlockFieldType;
static inline gint
rgb_to_y (gint r, gint g, gint b)
{
gint ret;
ret = (gint) (((19595 * r) >> 16) + ((38470 * g) >> 16) + ((7471 * b) >> 16));
ret = CLAMP (ret, 0, 255);
return ret;
}
static inline gint
rgb_to_u (gint r, gint g, gint b)
{
gint ret;
ret =
(gint) (-((11059 * r) >> 16) - ((21709 * g) >> 16) + ((32768 * b) >> 16) +
128);
ret = CLAMP (ret, 0, 255);
return ret;
}
static inline gint
rgb_to_v (gint r, gint g, gint b)
{
gint ret;
ret =
(gint) (((32768 * r) >> 16) - ((27439 * g) >> 16) - ((5329 * b) >> 16) +
128);
ret = CLAMP (ret, 0, 255);
return ret;
}
static DVBSubObject *
get_object (DvbSub * dvb_sub, guint16 object_id)
{
DVBSubObject *ptr = dvb_sub->object_list;
while (ptr && ptr->id != object_id) {
ptr = ptr->next;
}
return ptr;
}
static DVBSubCLUT *
get_clut (DvbSub * dvb_sub, gint clut_id)
{
DVBSubCLUT *ptr = dvb_sub->clut_list;
while (ptr && ptr->id != clut_id) {
ptr = ptr->next;
}
return ptr;
}
static DVBSubRegion *
get_region (DvbSub * dvb_sub, guint8 region_id)
{
DVBSubRegion *ptr = dvb_sub->region_list;
while (ptr && ptr->id != region_id) {
ptr = ptr->next;
}
return ptr;
}
static void
delete_region_display_list (DvbSub * dvb_sub, DVBSubRegion * region)
{
DVBSubObject *object, *obj2;
DVBSubObject **obj2_ptr;
DVBSubObjectDisplay *display, *obj_disp, **obj_disp_ptr;
while (region->display_list) {
display = region->display_list;
object = get_object (dvb_sub, display->object_id);
if (object) {
obj_disp_ptr = &object->display_list;
obj_disp = *obj_disp_ptr;
while (obj_disp && obj_disp != display) {
obj_disp_ptr = &obj_disp->object_list_next;
obj_disp = *obj_disp_ptr;
}
if (obj_disp) {
*obj_disp_ptr = obj_disp->object_list_next;
if (!object->display_list) {
obj2_ptr = (DVBSubObject **) & dvb_sub->object_list; /* FIXME: Evil casting */
obj2 = *obj2_ptr;
while (obj2 != object) {
g_assert (obj2);
obj2_ptr = &obj2->next;
obj2 = *obj2_ptr;
}
*obj2_ptr = obj2->next;
g_slice_free (DVBSubObject, obj2);
}
}
}
region->display_list = display->region_list_next;
g_slice_free (DVBSubObjectDisplay, display);
}
}
static void
delete_state (DvbSub * dvb_sub)
{
DVBSubRegion *region;
while (dvb_sub->region_list) {
region = dvb_sub->region_list;
dvb_sub->region_list = region->next;
delete_region_display_list (dvb_sub, region);
if (region->pbuf)
g_free (region->pbuf);
g_slice_free (DVBSubRegion, region);
}
g_slice_free_chain (DVBSubCLUT, dvb_sub->clut_list, next);
dvb_sub->clut_list = NULL;
/* Should already be NULL */
g_warn_if_fail (dvb_sub->object_list == NULL);
}
static void
dvb_sub_init (void)
{
int i, r, g, b, a = 0;
GST_DEBUG_CATEGORY_INIT (dvbsub_debug, "dvbsub", 0, "dvbsuboverlay parser");
/* Initialize the static default_clut structure, from which other clut
* structures are initialized from (to start off with default CLUTs
* as defined in the specification). */
default_clut.id = -1;
default_clut.clut4[0] = RGBA_TO_AYUV (0, 0, 0, 0);
default_clut.clut4[1] = RGBA_TO_AYUV (255, 255, 255, 255);
default_clut.clut4[2] = RGBA_TO_AYUV (0, 0, 0, 255);
default_clut.clut4[3] = RGBA_TO_AYUV (127, 127, 127, 255);
default_clut.clut16[0] = RGBA_TO_AYUV (0, 0, 0, 0);
for (i = 1; i < 16; i++) {
if (i < 8) {
r = (i & 1) ? 255 : 0;
g = (i & 2) ? 255 : 0;
b = (i & 4) ? 255 : 0;
} else {
r = (i & 1) ? 127 : 0;
g = (i & 2) ? 127 : 0;
b = (i & 4) ? 127 : 0;
}
default_clut.clut16[i] = RGBA_TO_AYUV (r, g, b, 255);
}
default_clut.clut256[0] = RGBA_TO_AYUV (0, 0, 0, 0);
for (i = 1; i < 256; i++) {
if (i < 8) {
r = (i & 1) ? 255 : 0;
g = (i & 2) ? 255 : 0;
b = (i & 4) ? 255 : 0;
a = 63;
} else {
switch (i & 0x88) {
case 0x00:
r = ((i & 1) ? 85 : 0) + ((i & 0x10) ? 170 : 0);
g = ((i & 2) ? 85 : 0) + ((i & 0x20) ? 170 : 0);
b = ((i & 4) ? 85 : 0) + ((i & 0x40) ? 170 : 0);
a = 255;
break;
case 0x08:
r = ((i & 1) ? 85 : 0) + ((i & 0x10) ? 170 : 0);
g = ((i & 2) ? 85 : 0) + ((i & 0x20) ? 170 : 0);
b = ((i & 4) ? 85 : 0) + ((i & 0x40) ? 170 : 0);
a = 127;
break;
case 0x80:
r = 127 + ((i & 1) ? 43 : 0) + ((i & 0x10) ? 85 : 0);
g = 127 + ((i & 2) ? 43 : 0) + ((i & 0x20) ? 85 : 0);
b = 127 + ((i & 4) ? 43 : 0) + ((i & 0x40) ? 85 : 0);
a = 255;
break;
case 0x88:
r = ((i & 1) ? 43 : 0) + ((i & 0x10) ? 85 : 0);
g = ((i & 2) ? 43 : 0) + ((i & 0x20) ? 85 : 0);
b = ((i & 4) ? 43 : 0) + ((i & 0x40) ? 85 : 0);
a = 255;
break;
}
}
default_clut.clut256[i] = RGBA_TO_AYUV (r, g, b, a);
}
}
static void
_dvb_sub_parse_page_segment (DvbSub * dvb_sub, guint16 page_id, guint8 * buf,
gint buf_size)
{ /* FIXME: Use guint for buf_size here and in many other places? */
DVBSubRegionDisplay *display;
DVBSubRegionDisplay *tmp_display_list, **tmp_ptr;
const guint8 *buf_end = buf + buf_size;
guint8 region_id;
guint8 page_state;
if (buf_size < 1)
return;
dvb_sub->page_time_out = *buf++;
page_state = ((*buf++) >> 2) & 3;
#ifndef GST_DISABLE_GST_DEBUG
{
static const gchar *page_state_str[4] = {
"Normal case", "ACQUISITION POINT", "Mode Change", "RESERVED"
};
GST_DEBUG ("PAGE: page_id = %u, length = %d, page_time_out = %u secs, "
"page_state = %s", page_id, buf_size, dvb_sub->page_time_out,
page_state_str[page_state]);
}
#endif
if (page_state == 2) { /* Mode change */
delete_state (dvb_sub);
}
tmp_display_list = dvb_sub->display_list;
dvb_sub->display_list = NULL;
dvb_sub->display_list_size = 0;
while (buf + 5 < buf_end) {
region_id = *buf++;
buf += 1;
display = tmp_display_list;
tmp_ptr = &tmp_display_list;
while (display && display->region_id != region_id) {
tmp_ptr = &display->next;
display = display->next;
}
if (!display)
display = g_slice_new0 (DVBSubRegionDisplay);
display->region_id = region_id;
display->x_pos = GST_READ_UINT16_BE (buf);
buf += 2;
display->y_pos = GST_READ_UINT16_BE (buf);
buf += 2;
*tmp_ptr = display->next;
display->next = dvb_sub->display_list;
dvb_sub->display_list = display;
dvb_sub->display_list_size++;
GST_LOG ("PAGE: REGION information: ID = %u, address = %ux%u", region_id,
display->x_pos, display->y_pos);
}
while (tmp_display_list) {
display = tmp_display_list;
tmp_display_list = display->next;
g_slice_free (DVBSubRegionDisplay, display);
}
}
static void
_dvb_sub_parse_region_segment (DvbSub * dvb_sub, guint16 page_id, guint8 * buf,
gint buf_size)
{
const guint8 *buf_end = buf + buf_size;
guint8 region_id;
guint16 object_id;
DVBSubRegion *region;
DVBSubObject *object;
DVBSubObjectDisplay *object_display;
gboolean fill;
if (buf_size < 10)
return;
region_id = *buf++;
region = get_region (dvb_sub, region_id);
if (!region) { /* Create a new region */
region = g_slice_new0 (DVBSubRegion);
region->id = region_id;
region->next = dvb_sub->region_list;
dvb_sub->region_list = region;
}
fill = ((*buf++) >> 3) & 1;
region->width = GST_READ_UINT16_BE (buf);
buf += 2;
region->height = GST_READ_UINT16_BE (buf);
buf += 2;
if (region->width * region->height != region->buf_size) { /* FIXME: Read closer from spec what happens when dimensions change */
if (region->pbuf)
g_free (region->pbuf);
region->buf_size = region->width * region->height;
region->pbuf = g_malloc (region->buf_size); /* TODO: We can probably use GSlice here if careful about freeing while buf_size still records the correct size */
fill = 1; /* FIXME: Validate from spec that fill is forced on (in the following codes context) when dimensions change */
}
region->depth = 1 << (((*buf++) >> 2) & 7);
if (region->depth < 2 || region->depth > 8) {
GST_WARNING ("region depth %d is invalid", region->depth);
region->depth = 4; /* FIXME: Check from spec this is the default? */
}
region->clut = *buf++;
if (region->depth == 8) {
region->bgcolor = *buf++;
buf += 1; /* Skip undefined 4-bit and 2-bit field */
} else {
buf += 1;
if (region->depth == 4)
region->bgcolor = (((*buf++) >> 4) & 15);
else
region->bgcolor = (((*buf++) >> 2) & 3);
}
GST_DEBUG ("REGION: id = %u, (%ux%u)@%u-bit", region_id, region->width,
region->height, region->depth);
if (fill) {
memset (region->pbuf, region->bgcolor, region->buf_size);
GST_DEBUG ("REGION: filling region (%u) with bgcolor = %u", region->id,
region->bgcolor);
}
delete_region_display_list (dvb_sub, region); /* Delete the region display list for current region - FIXME: why? */
while (buf + 6 <= buf_end) {
object_id = GST_READ_UINT16_BE (buf);
buf += 2;
object = get_object (dvb_sub, object_id);
if (!object) {
object = g_slice_new0 (DVBSubObject);
object->id = object_id;
object->next = dvb_sub->object_list;
dvb_sub->object_list = object;
}
object->type = (*buf) >> 6;
object_display = g_slice_new0 (DVBSubObjectDisplay);
object_display->object_id = object_id;
object_display->region_id = region_id;
object_display->x_pos = GST_READ_UINT16_BE (buf) & 0xfff;
buf += 2;
object_display->y_pos = GST_READ_UINT16_BE (buf) & 0xfff;
buf += 2;
if ((object->type == 1 || object->type == 2) && buf + 2 <= buf_end) {
object_display->fgcolor = *buf++;
object_display->bgcolor = *buf++;
}
object_display->region_list_next = region->display_list;
region->display_list = object_display;
object_display->object_list_next = object->display_list;
object->display_list = object_display;
GST_DEBUG ("REGION DATA: object_id = %u, region_id = %u, pos = %ux%u, "
"obj_type = %u", object->id, region->id, object_display->x_pos,
object_display->y_pos, object->type);
if (object->type == 1 || object->type == 2) {
GST_DEBUG ("REGION DATA: fgcolor = %u, bgcolor = %u",
object_display->fgcolor, object_display->bgcolor);
}
}
}
static void
_dvb_sub_parse_clut_segment (DvbSub * dvb_sub, guint16 page_id, guint8 * buf,
gint buf_size)
{
const guint8 *buf_end = buf + buf_size;
guint8 clut_id;
DVBSubCLUT *clut;
int entry_id, depth, full_range;
int y, cr, cb, alpha;
GST_MEMDUMP ("DVB clut packet", buf, buf_size);
clut_id = *buf++;
buf += 1;
clut = get_clut (dvb_sub, clut_id);
if (!clut) {
clut = g_slice_new (DVBSubCLUT);
memcpy (clut, &default_clut, sizeof (DVBSubCLUT));
clut->id = clut_id;
clut->next = dvb_sub->clut_list;
dvb_sub->clut_list = clut;
}
while (buf + 4 < buf_end) {
entry_id = *buf++;
depth = (*buf) & 0xe0;
if (depth == 0) {
GST_WARNING ("Invalid clut depth 0x%x!", *buf);
return;
}
full_range = (*buf++) & 1;
if (full_range) {
y = *buf++;
cr = *buf++;
cb = *buf++;
alpha = *buf++;
} else {
y = buf[0] & 0xfc;
cr = (((buf[0] & 3) << 2) | ((buf[1] >> 6) & 3)) << 4;
cb = (buf[1] << 2) & 0xf0;
alpha = (buf[1] << 6) & 0xc0;
buf += 2;
}
if (y == 0)
alpha = 0xff;
GST_DEBUG ("CLUT DEFINITION: clut %d := (%d,%d,%d,%d)", entry_id, y, cb, cr,
alpha);
if (depth & 0x80)
clut->clut4[entry_id] = AYUV (y, cb, cr, 255 - alpha);
if (depth & 0x40)
clut->clut16[entry_id] = AYUV (y, cb, cr, 255 - alpha);
if (depth & 0x20)
clut->clut256[entry_id] = AYUV (y, cb, cr, 255 - alpha);
}
}
// FFMPEG-FIXME: The same code in ffmpeg is much more complex, it could use the same
// FFMPEG-FIXME: refactoring as done here
static int
_dvb_sub_read_2bit_string (guint8 * destbuf, gint dbuf_len,
const guint8 ** srcbuf, gint buf_size, guint8 non_mod, guint8 * map_table)
{
GstBitReader gb = GST_BIT_READER_INIT (*srcbuf, buf_size);
/* FIXME: Handle FALSE returns from gst_bit_reader_get_* calls? */
gboolean stop_parsing = FALSE;
guint32 bits = 0;
guint32 pixels_read = 0;
GST_TRACE ("dbuf_len = %d", dbuf_len);
/* Need at least 2 bits remaining */
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 1)) {
guint run_length = 0, clut_index = 0;
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
if (bits) { /* 2-bit_pixel-code */
run_length = 1;
clut_index = bits;
} else { /* 2-bit_zero */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 1) { /* switch_1 == '1' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 3);
run_length += 3;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
} else { /* switch_1 == '0' */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 1) { /* switch_2 == '1' */
run_length = 1; /* 1x pseudo-colour '00' */
} else { /* switch_2 == '0' */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
switch (bits) { /* switch_3 */
case 0x0: /* end of 2-bit/pixel_code_string */
stop_parsing = TRUE;
break;
case 0x1: /* two pixels shall be set to pseudo colour (entry) '00' */
run_length = 2;
break;
case 0x2: /* the following 6 bits contain run length coded pixel data */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
run_length += 12;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
break;
case 0x3: /* the following 10 bits contain run length coded pixel data */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
run_length += 29;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
break;
}
}
}
}
/* If run_length is zero, continue. Only case happening is when
* stop_parsing is TRUE too, so next cycle shouldn't run */
if (run_length == 0)
continue;
/* Trim the run_length to not go beyond the line end and consume
* it from remaining length of dest line */
run_length = MIN (run_length, dbuf_len);
dbuf_len -= run_length;
/* Make clut_index refer to the index into the desired bit depths
* CLUT definition table */
if (map_table)
clut_index = map_table[clut_index]; /* now clut_index signifies the index into map_table dest */
/* Now we can simply memset run_length count of destination bytes
* to clut_index, but only if not non_modifying */
GST_TRACE ("RUNLEN: setting %u pixels to color 0x%x in destination buffer, "
"dbuf_len left is %d pixels", run_length, clut_index, dbuf_len);
if (!(non_mod == 1 && clut_index == 1))
memset (destbuf, clut_index, run_length);
destbuf += run_length;
pixels_read += run_length;
}
// FIXME: Test skip_to_byte instead of adding 7 bits, once everything else is working good
//gst_bit_reader_skip_to_byte (&gb);
*srcbuf += (gst_bit_reader_get_pos (&gb) + 7) >> 3;
GST_TRACE ("PIXEL: returning, read %u pixels", pixels_read);
// FIXME: Shouldn't need this variable if tracking things in the loop better
return pixels_read;
}
// FFMPEG-FIXME: The same code in ffmpeg is much more complex, it could use the same
// FFMPEG-FIXME: refactoring as done here, explained in commit 895296c3
static int
_dvb_sub_read_4bit_string (guint8 * destbuf, gint dbuf_len,
const guint8 ** srcbuf, gint buf_size, guint8 non_mod, guint8 * map_table)
{
GstBitReader gb = GST_BIT_READER_INIT (*srcbuf, buf_size);
/* FIXME: Handle FALSE returns from gst_bit_reader_get_* calls? */
gboolean stop_parsing = FALSE;
guint32 bits = 0;
guint32 pixels_read = 0;
GST_TRACE ("RUNLEN: srcbuf position %p, buf_size = %d; destination buffer "
"size is %d @ %p", *srcbuf, buf_size, dbuf_len, destbuf);
/* Need at least 4 bits */
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 3)) {
guint run_length = 0, clut_index = 0;
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
if (bits) {
run_length = 1;
clut_index = bits;
} else {
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_1 == '0' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 3);
if (!run_length) {
stop_parsing = TRUE;
} else {
run_length += 2;
}
} else { /* switch_1 == '1' */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_2 == '0' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
run_length += 4;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
} else { /* switch_2 == '1' */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 2);
switch (bits) {
case 0x0: /* switch_3 == '00' */
run_length = 1; /* 1 pixel of pseudo-color 0 */
break;
case 0x1: /* switch_3 == '01' */
run_length = 2; /* 2 pixels of pseudo-color 0 */
break;
case 0x2: /* switch_3 == '10' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
run_length += 9;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
break;
case 0x3: /* switch_3 == '11' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
run_length += 25;
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 4);
break;
}
}
}
}
/* If run_length is zero, continue. Only case happening is when
* stop_parsing is TRUE too, so next cycle shouldn't run */
if (run_length == 0)
continue;
/* Trim the run_length to not go beyond the line end and consume
* it from remaining length of dest line */
run_length = MIN (run_length, dbuf_len);
dbuf_len -= run_length;
/* Make clut_index refer to the index into the desired bit depths
* CLUT definition table */
if (map_table)
clut_index = map_table[clut_index]; /* now clut_index signifies the index into map_table dest */
/* Now we can simply memset run_length count of destination bytes
* to clut_index, but only if not non_modifying */
GST_TRACE ("RUNLEN: setting %u pixels to color 0x%x in destination buffer; "
"dbuf_len left is %d pixels", run_length, clut_index, dbuf_len);
if (!(non_mod == 1 && clut_index == 1))
memset (destbuf, clut_index, run_length);
destbuf += run_length;
pixels_read += run_length;
}
// FIXME: Test skip_to_byte instead of adding 7 bits, once everything else is working good
//gst_bit_reader_skip_to_byte (&gb);
*srcbuf += (gst_bit_reader_get_pos (&gb) + 7) >> 3;
GST_LOG ("Returning with %u pixels read", pixels_read);
// FIXME: Shouldn't need this variable if tracking things in the loop better
return pixels_read;
}
static int
_dvb_sub_read_8bit_string (guint8 * destbuf, gint dbuf_len,
const guint8 ** srcbuf, gint buf_size, guint8 non_mod, guint8 * map_table)
{
GstBitReader gb = GST_BIT_READER_INIT (*srcbuf, buf_size);
/* FIXME: Handle FALSE returns from gst_bit_reader_get_* calls? */
gboolean stop_parsing = FALSE;
guint32 bits = 0;
guint32 pixels_read = 0;
GST_LOG ("dbuf_len = %d", dbuf_len);
/* FFMPEG-FIXME: ffmpeg uses a manual byte walking algorithm, which might be more performant,
* FFMPEG-FIXME: but it does almost absolutely no buffer length checking, so could walk over
* FFMPEG-FIXME: memory boundaries. While we don't check gst_bit_reader_get_bits_uint32
* FFMPEG-FIXME: return values either and therefore might get some pixels corrupted, we at
* FFMPEG-FIXME: lest have no chance of reading memory we don't own and visual corruption
* FFMPEG-FIXME: is guaranteed anyway when not all bytes are present */
/* Rephrased - it's better to work with bytes with default value '0' instead of reading from memory we don't own. */
while (!stop_parsing && (gst_bit_reader_get_remaining (&gb) > 7)) {
guint run_length = 0, clut_index = 0;
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
if (bits) { /* 8-bit_pixel-code */
run_length = 1;
clut_index = bits;
} else { /* 8-bit_zero */
bits = gst_bit_reader_get_bits_uint32_unchecked (&gb, 1);
if (bits == 0) { /* switch_1 == '0' */
/* run_length_1-127 for pseudo-colour _entry) '0x00' */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 7);
if (run_length == 0) { /* end_of_string_signal */
stop_parsing = TRUE;
}
} else { /* switch_1 == '1' */
/* run_length_3-127 */
run_length = gst_bit_reader_get_bits_uint32_unchecked (&gb, 7);
clut_index = gst_bit_reader_get_bits_uint32_unchecked (&gb, 8);
if (run_length < 3) {
GST_WARNING ("runlength value was %u, but the spec requires it "
"must be >=3", run_length);
}
}
}
/* If run_length is zero, continue. Only case happening is when
* stop_parsing is TRUE too, so next cycle shouldn't run */
if (run_length == 0)
continue;
/* Trim the run_length to not go beyond the line end and consume
* it from remaining length of dest line */
run_length = MIN (run_length, dbuf_len);
dbuf_len -= run_length;
/* Make clut_index refer to the index into the desired bit depths
* CLUT definition table */
if (map_table)
clut_index = map_table[clut_index]; /* now clut_index signifies the index into map_table dest */
/* Now we can simply memset run_length count of destination bytes
* to clut_index, but only if not non_modifying */
GST_TRACE ("RUNLEN: setting %u pixels to color 0x%x in destination buffer; "
"dbuf_len left is %d pixels", run_length, clut_index, dbuf_len);
if (!(non_mod == 1 && clut_index == 1))
memset (destbuf, clut_index, run_length);
destbuf += run_length;
pixels_read += run_length;
}
GST_LOG ("Returning with %u pixels read", pixels_read);
*srcbuf += (gst_bit_reader_get_pos (&gb) + 7) >> 3;
// FIXME: Shouldn't need this variable if tracking things in the loop better
return pixels_read;
}
static void
_dvb_sub_parse_pixel_data_block (DvbSub * dvb_sub,
DVBSubObjectDisplay * display, const guint8 * buf, gint buf_size,
DvbSubPixelDataSubBlockFieldType top_bottom, guint8 non_mod)
{
DVBSubRegion *region = get_region (dvb_sub, display->region_id);
const guint8 *buf_end = buf + buf_size;
guint8 *pbuf;
int x_pos, y_pos;
int i;
gboolean dest_buf_filled = FALSE;
guint8 map2to4[] = { 0x0, 0x7, 0x8, 0xf };
guint8 map2to8[] = { 0x00, 0x77, 0x88, 0xff };
guint8 map4to8[] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff
};
guint8 *map_table;
GST_LOG ("DVB pixel block size %d, %s field:", buf_size,
top_bottom ? "bottom" : "top");
GST_MEMDUMP ("packet", buf, buf_size);
if (region == NULL) {
GST_LOG ("Region is NULL, returning");
return;
}
pbuf = region->pbuf;
x_pos = display->x_pos;
y_pos = display->y_pos;
if ((y_pos & 1) != top_bottom)
y_pos++;
while (buf < buf_end) {
GST_LOG ("Iteration start, %u bytes remaining; buf = %p, "
"buf_end = %p; Region is number %u, with a dimension of %dx%d; "
"We are at position %dx%d", (guint) (buf_end - buf), buf, buf_end,
region->id, region->width, region->height, x_pos, y_pos);
// FFMPEG-FIXME: ffmpeg doesn't check for equality and so can overflow destination buffer later on with bad input data
// FFMPEG-FIXME: However that makes it warn on end_of_object_line and map tables as well, so we add the dest_buf_filled tracking
// FIXME: Removed x_pos checking here, because we don't want to turn dest_buf_filled to TRUE permanently in that case
// FIXME: We assume that region->width - x_pos as dbuf_len to read_nbit_string will take care of that case nicely;
// FIXME: That is, that read_nbit_string never scribbles anything if dbuf_len passed to it is zero due to this.
if (y_pos >= region->height) {
dest_buf_filled = TRUE;
}
switch (*buf++) {
case 0x10:
if (dest_buf_filled) {
/* FIXME: Be more verbose */
GST_WARNING ("Invalid object location for data_type 0x%x!",
*(buf - 1));
GST_MEMDUMP ("Remaining data after invalid object location:", buf,
(guint) (buf_end - buf));
return;
}
if (region->depth == 8)
map_table = map2to8;
else if (region->depth == 4)
map_table = map2to4;
else
map_table = NULL;
// FFMPEG-FIXME: ffmpeg code passes buf_size instead of buf_end - buf, and could
// FFMPEG-FIXME: therefore potentially walk over the memory area we own
x_pos +=
_dvb_sub_read_2bit_string (pbuf + (y_pos * region->width) + x_pos,
region->width - x_pos, &buf, buf_end - buf, non_mod, map_table);
break;
case 0x11:
if (dest_buf_filled) {
/* FIXME: Be more verbose */
GST_WARNING ("Invalid object location for data_type 0x%x!",
*(buf - 1));
GST_MEMDUMP ("Remaining data after invalid object location:", buf,
buf_end - buf);
return; // FIXME: Perhaps tell read_nbit_string that dbuf_len is zero and let it walk the bytes regardless? (Same FIXME for 2bit and 8bit)
}
if (region->depth < 4) {
GST_WARNING ("4-bit pixel string in %d-bit region!", region->depth);
return;
}
if (region->depth == 8)
map_table = map4to8;
else
map_table = NULL;
GST_LOG ("READ_4BIT_STRING: String data into position %dx%d; "
"buf before is %p", x_pos, y_pos, buf);
// FFMPEG-FIXME: ffmpeg code passes buf_size instead of buf_end - buf, and could
// FFMPEG-FIXME: therefore potentially walk over the memory area we own
x_pos +=
_dvb_sub_read_4bit_string (pbuf + (y_pos * region->width) + x_pos,
region->width - x_pos, &buf, buf_end - buf, non_mod, map_table);
GST_DEBUG ("READ_4BIT_STRING finished: buf pointer now %p", buf);
break;
case 0x12:
if (dest_buf_filled) {
/* FIXME: Be more verbose */
GST_WARNING ("Invalid object location for data_type 0x%x!",
*(buf - 1));
GST_MEMDUMP ("Remaining data after invalid object location:",
buf, (guint) (buf_end - buf));
return;
}
if (region->depth < 8) {
GST_WARNING ("8-bit pixel string in %d-bit region!", region->depth);
return;
}
// FFMPEG-FIXME: ffmpeg code passes buf_size instead of buf_end - buf, and could
// FFMPEG-FIXME: therefore potentially walk over the memory area we own
x_pos +=
_dvb_sub_read_8bit_string (pbuf + (y_pos * region->width) + x_pos,
region->width - x_pos, &buf, buf_end - buf, non_mod, NULL);
break;
case 0x20:
GST_DEBUG ("handling map2to4 table data");
/* FIXME: I don't see any guards about buffer size here - buf++ happens with the switch, but
* FIXME: buffer is walked without length checks? Same deal in other map table cases */
map2to4[0] = (*buf) >> 4;
map2to4[1] = (*buf++) & 0xf;
map2to4[2] = (*buf) >> 4;
map2to4[3] = (*buf++) & 0xf;
break;
case 0x21:
GST_DEBUG ("handling map2to8 table data");
for (i = 0; i < 4; i++)
map2to8[i] = *buf++;
break;
case 0x22:
GST_DEBUG ("handling map4to8 table data");
for (i = 0; i < 16; i++)
map4to8[i] = *buf++;
break;
case 0xf0:
GST_DEBUG ("end of object line code encountered");
x_pos = display->x_pos;
y_pos += 2;
break;
default:
/* FIXME: Do we consume word align stuffing byte that could follow top/bottom data? */
GST_WARNING ("Unknown/unsupported pixel block 0x%x", *(buf - 1));
}
}
}
static void
_dvb_sub_parse_object_segment (DvbSub * dvb_sub, guint16 page_id, guint8 * buf,
gint buf_size)
{
const guint8 *buf_end = buf + buf_size;
guint object_id;
DVBSubObject *object;
guint8 coding_method, non_modifying_color;
object_id = GST_READ_UINT16_BE (buf);
buf += 2;
object = get_object (dvb_sub, object_id);
GST_DEBUG ("OBJECT: a new object segment has occurred for object_id = %u",
object_id);
if (!object) {
GST_WARNING ("Nothing known about object with ID %u yet, bailing out",
object_id);
return;
}
coding_method = ((*buf) >> 2) & 3;
non_modifying_color = ((*buf++) >> 1) & 1;
if (coding_method == 0) {
const guint8 *block;
DVBSubObjectDisplay *display;
guint16 top_field_len, bottom_field_len;
top_field_len = GST_READ_UINT16_BE (buf);
buf += 2;
bottom_field_len = GST_READ_UINT16_BE (buf);
buf += 2;
if (buf + top_field_len + bottom_field_len > buf_end) {
GST_WARNING ("Field data size too large");
return;
}
/* FIXME: Potential optimization opportunity here - parse the object pixmap only once, and copy it to all the
* FIXME: regions that need it. One object being in multiple regions is a rare occurrence in real life, however */
for (display = object->display_list; display;
display = display->object_list_next) {
block = buf;
GST_DEBUG ("OBJECT: parsing top and bottom part of object id %d; "
"top_field_len = %u, bottom_field_len = %u",
display->object_id, top_field_len, bottom_field_len);
_dvb_sub_parse_pixel_data_block (dvb_sub, display, block, top_field_len,
TOP_FIELD, non_modifying_color);
if (bottom_field_len > 0)
block = buf + top_field_len;
else
bottom_field_len = top_field_len;
_dvb_sub_parse_pixel_data_block (dvb_sub, display, block,
bottom_field_len, BOTTOM_FIELD, non_modifying_color);
}
} else if (coding_method == 1) {
GST_FIXME ("'a string of characters' coding method not supported yet!");
} else {
GST_WARNING ("Unknown object coding 0x%x", coding_method);
}
}
static gint
_dvb_sub_parse_display_definition_segment (DvbSub * dvb_sub, guint8 * buf,
gint buf_size)
{
int dds_version, info_byte;
if (buf_size < 5)
return -1;
info_byte = *buf++;
dds_version = info_byte >> 4;
if (dvb_sub->display_def.version == dds_version)
return 0; /* already have this display definition version */
dvb_sub->display_def.version = dds_version;
dvb_sub->display_def.display_width = GST_READ_UINT16_BE (buf) + 1;
buf += 2;
dvb_sub->display_def.display_height = GST_READ_UINT16_BE (buf) + 1;
buf += 2;
dvb_sub->display_def.window_flag = info_byte & 1 << 3;
if (buf_size >= 13 && dvb_sub->display_def.window_flag) {
dvb_sub->display_def.window_x = GST_READ_UINT16_BE (buf);
buf += 2;
dvb_sub->display_def.window_width =
GST_READ_UINT16_BE (buf) - dvb_sub->display_def.window_x + 1;
buf += 2;
dvb_sub->display_def.window_y = GST_READ_UINT16_BE (buf);
buf += 2;
dvb_sub->display_def.window_height =
GST_READ_UINT16_BE (buf) - dvb_sub->display_def.window_y + 1;
}
return 0;
}
static gint
_dvb_sub_parse_end_of_display_set (DvbSub * dvb_sub, guint16 page_id,
guint64 pts)
{
DVBSubRegionDisplay *display;
DVBSubtitles *sub;
DVBSubCLUT *clut;
guint32 *clut_table;
int i;
GST_DEBUG ("DISPLAY SET END: page_id = %u", page_id);
sub = g_slice_new0 (DVBSubtitles);
#if 0 /* FIXME: PTS stuff not figured out yet */
sub->start_display_time = 0;
sub->end_display_time = priv->page_time_out * 1000;
sub->format = 0; /* 0 = graphics */
#endif
/* N.B. g_new0() will return NULL if num_rects is 0 */
sub->num_rects = dvb_sub->display_list_size;
sub->rects = g_new0 (DVBSubtitleRect, sub->num_rects);
i = 0;
/* copy subtitle display and window information */
sub->display_def = dvb_sub->display_def;
for (display = dvb_sub->display_list; display; display = display->next) {
DVBSubtitleRect *rect;
DVBSubRegion *region;
region = get_region (dvb_sub, display->region_id);
if (!region)
continue;
rect = &sub->rects[i];
rect->x = display->x_pos;
rect->y = display->y_pos;
rect->w = region->width;
rect->h = region->height;
#if 0 /* FIXME: Don't think we need to save the number of colors in the palette when we are saving as RGBA? */
rect->nb_colors = 16;
#endif
#if 0 /* FIXME: Needed to be specified once we support strings of characters based subtitles */
rect->type = SUBTITLE_BITMAP;
#endif
rect->pict.rowstride = region->width;
rect->pict.palette_bits_count = region->depth;
clut = get_clut (dvb_sub, region->clut);
if (!clut)
clut = &default_clut;
switch (region->depth) {
case 2:
clut_table = clut->clut4;
break;
case 8:
clut_table = clut->clut256;
break;
case 4:
default:
clut_table = clut->clut16;
break;
}
/* FIXME: Tweak this to be saved in a format most suitable for Qt and GStreamer instead.
* Currently kept in AVPicture for quick save_display_set testing */
rect->pict.palette = g_malloc ((1 << region->depth) * sizeof (guint32)); /* FIXME: Can we use GSlice here? */
memcpy (rect->pict.palette, clut_table,
(1 << region->depth) * sizeof (guint32));
GST_MEMDUMP ("rect->pict.data.palette content",
(guint8 *) rect->pict.palette, (1 << region->depth) * sizeof (guint32));
rect->pict.data = g_malloc (region->buf_size); /* FIXME: Can we use GSlice here? */
memcpy (rect->pict.data, region->pbuf, region->buf_size);
GST_DEBUG ("DISPLAY: an object rect created: iteration %u, "
"pos: %d:%d, size: %dx%d", i, rect->x, rect->y, rect->w, rect->h);
GST_MEMDUMP ("rect->pict.data content", rect->pict.data, region->buf_size);
++i;
}
sub->pts = pts;
sub->page_time_out = dvb_sub->page_time_out;
sub->num_rects = i;
if (dvb_sub->callbacks.new_data) {
dvb_sub->callbacks.new_data (dvb_sub, sub, dvb_sub->user_data);
} else {
/* No-one responsible to clean up memory, so do it ourselves */
/* FIXME: Just don't bother with all this palette image creation in the first place then... */
dvb_subtitles_free (sub);
}
return 1; /* FIXME: The caller of this function is probably supposed to do something with the return value */
}
void
dvb_subtitles_free (DVBSubtitles * sub)
{
int i;
if (sub == NULL)
return;
/* Now free up all the temporary memory we allocated */
for (i = 0; i < sub->num_rects; ++i) {
g_free (sub->rects[i].pict.palette);
g_free (sub->rects[i].pict.data);
}
g_free (sub->rects);
g_slice_free (DVBSubtitles, sub);
}
DvbSub *
dvb_sub_new (void)
{
static gsize inited = 0;
DvbSub *sub;
if (g_once_init_enter (&inited)) {
dvb_sub_init ();
g_once_init_leave (&inited, TRUE);
}
sub = g_slice_new0 (DvbSub);
/* TODO: Add initialization code here */
/* FIXME: Do we have a reason to initiate the members to zero, or are we guaranteed that anyway? */
sub->region_list = NULL;
sub->object_list = NULL;
sub->page_time_out = 0; /* FIXME: Maybe 255 instead? */
sub->pes_buffer = g_string_new (NULL);
/* display/window information */
sub->display_def.version = -1;
sub->display_def.window_flag = 0;
sub->display_def.display_width = 720;
sub->display_def.display_height = 576;
return sub;
}
void
dvb_sub_free (DvbSub * sub)
{
/* TODO: Add deinitalization code here */
/* FIXME: Clear up region_list contents */
delete_state (sub);
while (sub->display_list) {
DVBSubRegionDisplay *tmp = sub->display_list->next;
g_slice_free (DVBSubRegionDisplay, sub->display_list);
sub->display_list = tmp;
}
g_string_free (sub->pes_buffer, TRUE);
g_slice_free (DvbSub, sub);
}
#define DVB_SUB_SEGMENT_PAGE_COMPOSITION 0x10
#define DVB_SUB_SEGMENT_REGION_COMPOSITION 0x11
#define DVB_SUB_SEGMENT_CLUT_DEFINITION 0x12
#define DVB_SUB_SEGMENT_OBJECT_DATA 0x13
#define DVB_SUB_SEGMENT_DISPLAY_DEFINITION 0x14
#define DVB_SUB_SEGMENT_END_OF_DISPLAY_SET 0x80
#define DVB_SUB_SEGMENT_STUFFING 0xFF
#define DVB_SUB_SYNC_BYTE 0x0f
/**
* dvb_sub_feed_with_pts:
* @dvb_sub: a #DvbSub
* @pts: The PTS of the data
* @data: The data to feed to the parser
* @len: Length of the data
*
* Feeds the DvbSub parser with new binary data to parse,
* with an associated PTS value. E.g, data left after PES
* packet header has been already parsed, which contains
* the PTS information).
*
* Return value: -1 if data was unhandled (e.g, not a subtitle packet),
* -2 if data parsing was unsuccesful (e.g, length was invalid),
* 0 or positive if data was handled. If positive, then amount of data consumed on success. FIXME: List the positive return values.
*/
gint
dvb_sub_feed_with_pts (DvbSub * dvb_sub, guint64 pts, guint8 * data, gint len)
{
unsigned int pos = 0;
guint8 segment_type;
guint16 segment_len;
guint16 page_id;
GST_DEBUG ("pts=%" G_GUINT64_FORMAT " and length %d", pts, len);
g_return_val_if_fail (data != NULL || len == 0, -1);
if (G_UNLIKELY (data == NULL)) {
GST_DEBUG ("no data; forcing end-of-display-set");
_dvb_sub_parse_end_of_display_set (dvb_sub, 0, pts);
return 0;
}
if (len <= 3) { /* len(0x20 0x00 end_of_PES_data_field_marker) */
GST_WARNING ("Data length too short");
return -1;
}
if (data[pos++] != 0x20) {
GST_WARNING ("Tried to handle a PES packet private data that isn't a "
"subtitle packet (does not start with 0x20)");
return -1;
}
if (data[pos++] != 0x00) {
GST_WARNING ("'Subtitle stream in this PES packet' was not 0x00, so this "
"is in theory not a DVB subtitle stream (but some other subtitle "
"standard?); bailing out");
return -1;
}
while (data[pos++] == DVB_SUB_SYNC_BYTE) {
if ((len - pos) < (2 * 2 + 1)) {
GST_WARNING ("Data after SYNC BYTE too short, less than needed to "
"even get to segment_length");
return -2;
}
segment_type = data[pos++];
GST_DEBUG ("=== Segment type is 0x%x", segment_type);
page_id = (data[pos] << 8) | data[pos + 1];
GST_DEBUG ("page_id is 0x%x", page_id);
pos += 2;
segment_len = (data[pos] << 8) | data[pos + 1];
GST_DEBUG ("segment_length is %d (0x%x 0x%x)", segment_len, data[pos],
data[pos + 1]);
pos += 2;
if ((len - pos) < segment_len) {
GST_WARNING ("segment_length was told to be %u, but we only have "
"%d bytes left", segment_len, len - pos);
return -2;
}
// TODO: Parse the segment per type (this is probably a leftover TODO that is now done?)
/* FIXME: Handle differing PTS values - all segments of a given display set must be with the same PTS,
* FIXME: but we let it slip and just take it for granted in end_of_display_set */
switch (segment_type) {
case DVB_SUB_SEGMENT_PAGE_COMPOSITION:
GST_DEBUG ("Page composition segment at buffer pos %u", pos);
_dvb_sub_parse_page_segment (dvb_sub, page_id, data + pos, segment_len); /* FIXME: Not sure about args */
break;
case DVB_SUB_SEGMENT_REGION_COMPOSITION:
GST_DEBUG ("Region composition segment at buffer pos %u", pos);
_dvb_sub_parse_region_segment (dvb_sub, page_id, data + pos, segment_len); /* FIXME: Not sure about args */
break;
case DVB_SUB_SEGMENT_CLUT_DEFINITION:
GST_DEBUG ("CLUT definition segment at buffer pos %u", pos);
_dvb_sub_parse_clut_segment (dvb_sub, page_id, data + pos, segment_len); /* FIXME: Not sure about args */
break;
case DVB_SUB_SEGMENT_OBJECT_DATA:
GST_DEBUG ("Object data segment at buffer pos %u", pos);
_dvb_sub_parse_object_segment (dvb_sub, page_id, data + pos, segment_len); /* FIXME: Not sure about args */
break;
case DVB_SUB_SEGMENT_DISPLAY_DEFINITION:
GST_DEBUG ("display definition segment at buffer pos %u", pos);
_dvb_sub_parse_display_definition_segment (dvb_sub, data + pos,
segment_len);
break;
case DVB_SUB_SEGMENT_END_OF_DISPLAY_SET:
GST_DEBUG ("End of display set at buffer pos %u", pos);
_dvb_sub_parse_end_of_display_set (dvb_sub, page_id, pts); /* FIXME: Not sure about args */
break;
default:
GST_FIXME ("Unhandled segment type 0x%x", segment_type);
break;
}
pos += segment_len;
if (pos == len) {
GST_WARNING ("Data ended without a PES data end marker");
return 1;
}
}
GST_LOG ("Processed %d bytes out of %d", pos, len);
return pos;
}
/**
* dvb_sub_set_callbacks:
* @dvb_sub: a #DvbSub
* @callbacks: the callbacks to install
* @user_data: a user_data argument for the callback
*
* Set callback which will be executed when new subpictures are available.
*/
void
dvb_sub_set_callbacks (DvbSub * dvb_sub, DvbSubCallbacks * callbacks,
gpointer user_data)
{
g_return_if_fail (dvb_sub != NULL);
g_return_if_fail (callbacks != NULL);
dvb_sub->callbacks = *callbacks;
dvb_sub->user_data = user_data;
}