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-rw-r--r--libhb/decsub.c420
1 files changed, 420 insertions, 0 deletions
diff --git a/libhb/decsub.c b/libhb/decsub.c
new file mode 100644
index 000000000..72f742bd9
--- /dev/null
+++ b/libhb/decsub.c
@@ -0,0 +1,420 @@
+/* $Id: decsub.c,v 1.12 2005/04/14 17:37:54 titer Exp $
+
+ This file is part of the HandBrake source code.
+ Homepage: <http://handbrake.m0k.org/>.
+ It may be used under the terms of the GNU General Public License. */
+
+#include "hb.h"
+
+struct hb_work_object_s
+{
+ HB_WORK_COMMON;
+
+ hb_job_t * job;
+
+ uint8_t buf[0xFFFF];
+ int size_sub;
+ int size_got;
+ int size_rle;
+ int64_t pts;
+ int64_t pts_start;
+ int64_t pts_stop;
+ int x;
+ int y;
+ int width;
+ int height;
+
+ int offsets[2];
+ uint8_t lum[4];
+ uint8_t alpha[4];
+};
+
+
+/***********************************************************************
+ * Local prototypes
+ **********************************************************************/
+static void Close( hb_work_object_t ** _w );
+static int Work( hb_work_object_t * w, hb_buffer_t ** buf_in,
+ hb_buffer_t ** buf_out );
+static hb_buffer_t * Decode( hb_work_object_t * w );
+static void ParseControls( hb_work_object_t * w );
+static hb_buffer_t * CropSubtitle( hb_work_object_t * w,
+ uint8_t * raw );
+
+/***********************************************************************
+ * hb_work_decsub_init
+ ***********************************************************************
+ *
+ **********************************************************************/
+hb_work_object_t * hb_work_decsub_init( hb_job_t * job )
+{
+ hb_work_object_t * w = calloc( sizeof( hb_work_object_t ), 1 );
+ w->name = strdup( "Subtitle decoder" );
+ w->work = Work;
+ w->close = Close;
+
+ w->job = job;
+ w->pts = -1;
+
+ return w;
+}
+
+/***********************************************************************
+ * Close
+ ***********************************************************************
+ * Free memory
+ **********************************************************************/
+static void Close( hb_work_object_t ** _w )
+{
+ hb_work_object_t * w = *_w;
+ free( w->name );
+ free( w );
+ *_w = NULL;
+}
+
+/***********************************************************************
+ * Work
+ ***********************************************************************
+ *
+ **********************************************************************/
+static int Work( hb_work_object_t * w, hb_buffer_t ** buf_in,
+ hb_buffer_t ** buf_out )
+{
+ hb_buffer_t * in = *buf_in;
+
+ int size_sub, size_rle;
+
+ size_sub = ( in->data[0] << 8 ) | in->data[1];
+ size_rle = ( in->data[2] << 8 ) | in->data[3];
+
+ if( !w->size_sub )
+ {
+ /* We are looking for the start of a new subtitle */
+ if( size_sub && size_rle && size_sub > size_rle &&
+ in->size <= size_sub )
+ {
+ /* Looks all right so far */
+ w->size_sub = size_sub;
+ w->size_rle = size_rle;
+
+ memcpy( w->buf, in->data, in->size );
+ w->size_got = in->size;
+ w->pts = in->start;
+ }
+ }
+ else
+ {
+ /* We are waiting for the end of the current subtitle */
+ if( in->size <= w->size_sub - w->size_got )
+ {
+ memcpy( w->buf + w->size_got, in->data, in->size );
+ w->size_got += in->size;
+ if( in->start >= 0 )
+ {
+ w->pts = in->start;
+ }
+ }
+ }
+
+ *buf_out = NULL;
+
+ if( w->size_sub && w->size_sub == w->size_got )
+ {
+ /* We got a complete subtitle, decode it */
+ *buf_out = Decode( w );
+
+ /* Wait for the next one */
+ w->size_sub = 0;
+ w->size_got = 0;
+ w->size_rle = 0;
+ w->pts = -1;
+ }
+
+ return HB_WORK_OK;
+}
+
+static hb_buffer_t * Decode( hb_work_object_t * w )
+{
+ int code, line, col;
+ int offsets[2];
+ int * offset;
+ hb_buffer_t * buf;
+ uint8_t * buf_raw = NULL;
+
+ /* Get infos about the subtitle */
+ ParseControls( w );
+
+ /* Do the actual decoding now */
+ buf_raw = malloc( w->width * w->height * 2 );
+
+#define GET_NEXT_NIBBLE code = ( code << 4 ) | ( ( ( *offset & 1 ) ? \
+( w->buf[((*offset)>>1)] & 0xF ) : ( w->buf[((*offset)>>1)] >> 4 ) ) ); \
+(*offset)++
+
+ offsets[0] = w->offsets[0] * 2;
+ offsets[1] = w->offsets[1] * 2;
+
+ for( line = 0; line < w->height; line++ )
+ {
+ /* Select even or odd field */
+ offset = ( line & 1 ) ? &offsets[1] : &offsets[0];
+
+ for( col = 0; col < w->width; col += code >> 2 )
+ {
+ uint8_t * lum, * alpha;
+
+ code = 0;
+ GET_NEXT_NIBBLE;
+ if( code < 0x4 )
+ {
+ GET_NEXT_NIBBLE;
+ if( code < 0x10 )
+ {
+ GET_NEXT_NIBBLE;
+ if( code < 0x40 )
+ {
+ GET_NEXT_NIBBLE;
+ if( code < 0x100 )
+ {
+ /* End of line */
+ code |= ( w->width - col ) << 2;
+ }
+ }
+ }
+ }
+
+ lum = buf_raw;
+ alpha = lum + w->width * w->height;
+ memset( lum + line * w->width + col,
+ w->lum[code & 3], code >> 2 );
+ memset( alpha + line * w->width + col,
+ w->alpha[code & 3], code >> 2 );
+ }
+
+ /* Byte-align */
+ if( *offset & 1 )
+ {
+ (*offset)++;
+ }
+ }
+
+ /* Crop subtitle (remove transparent borders) */
+ buf = CropSubtitle( w, buf_raw );
+
+ free( buf_raw );
+
+ return buf;
+}
+
+/***********************************************************************
+ * ParseControls
+ ***********************************************************************
+ * Get the start and end dates (relative to the PTS from the PES
+ * header), the width and height of the subpicture and the colors and
+ * alphas used in it
+ **********************************************************************/
+static void ParseControls( hb_work_object_t * w )
+{
+ hb_job_t * job = w->job;
+ hb_title_t * title = job->title;
+
+ int i;
+ int command;
+ int date, next;
+
+ for( i = w->size_rle; ; )
+ {
+ date = ( w->buf[i] << 8 ) | w->buf[i+1]; i += 2;
+ next = ( w->buf[i] << 8 ) | w->buf[i+1]; i += 2;
+
+ for( ;; )
+ {
+ command = w->buf[i++];
+
+ if( command == 0xFF )
+ {
+ break;
+ }
+
+ switch( command )
+ {
+ case 0x00:
+ break;
+
+ case 0x01:
+ w->pts_start = w->pts + date * 900;
+ break;
+
+ case 0x02:
+ w->pts_stop = w->pts + date * 900;
+ break;
+
+ case 0x03:
+ {
+ int colors[4];
+ int j;
+
+ colors[0] = (w->buf[i+0]>>4)&0x0f;
+ colors[1] = (w->buf[i+0])&0x0f;
+ colors[2] = (w->buf[i+1]>>4)&0x0f;
+ colors[3] = (w->buf[i+1])&0x0f;
+
+ for( j = 0; j < 4; j++ )
+ {
+ uint32_t color = title->palette[colors[j]];
+ w->lum[3-j] = (color>>16) & 0xff;
+ }
+ i += 2;
+ break;
+ }
+ case 0x04:
+ {
+ w->alpha[3] = (w->buf[i+0]>>4)&0x0f;
+ w->alpha[2] = (w->buf[i+0])&0x0f;
+ w->alpha[1] = (w->buf[i+1]>>4)&0x0f;
+ w->alpha[0] = (w->buf[i+1])&0x0f;
+ i += 2;
+ break;
+ }
+ case 0x05:
+ {
+ w->x = (w->buf[i+0]<<4) | ((w->buf[i+1]>>4)&0x0f);
+ w->width = (((w->buf[i+1]&0x0f)<<8)| w->buf[i+2]) - w->x + 1;
+ w->y = (w->buf[i+3]<<4)| ((w->buf[i+4]>>4)&0x0f);
+ w->height = (((w->buf[i+4]&0x0f)<<8)| w->buf[i+5]) - w->y + 1;
+ i += 6;
+ break;
+ }
+ case 0x06:
+ {
+ w->offsets[0] = ( w->buf[i] << 8 ) | w->buf[i+1]; i += 2;
+ w->offsets[1] = ( w->buf[i] << 8 ) | w->buf[i+1]; i += 2;
+ break;
+ }
+ }
+ }
+
+ if( i > next )
+ {
+ break;
+ }
+ i = next;
+ }
+}
+
+/***********************************************************************
+ * CropSubtitle
+ ***********************************************************************
+ * Given a raw decoded subtitle, detects transparent borders and
+ * returns a cropped subtitle in a hb_buffer_t ready to be used by
+ * the renderer, or NULL if the subtitle was completely transparent
+ **********************************************************************/
+static int LineIsTransparent( hb_work_object_t * w, uint8_t * p )
+{
+ int i;
+ for( i = 0; i < w->width; i++ )
+ {
+ if( p[i] )
+ {
+ return 0;
+ }
+ }
+ return 1;
+}
+static int ColumnIsTransparent( hb_work_object_t * w, uint8_t * p )
+{
+ int i;
+ for( i = 0; i < w->height; i++ )
+ {
+ if( p[i*w->width] )
+ {
+ return 0;
+ }
+ }
+ return 1;
+}
+static hb_buffer_t * CropSubtitle( hb_work_object_t * w, uint8_t * raw )
+{
+ int i;
+ int crop[4] = { -1,-1,-1,-1 };
+ uint8_t * alpha;
+ int realwidth, realheight;
+ hb_buffer_t * buf;
+ uint8_t * lum_in, * lum_out, * alpha_in, * alpha_out;
+
+ alpha = raw + w->width * w->height;
+
+ /* Top */
+ for( i = 0; i < w->height; i++ )
+ {
+ if( !LineIsTransparent( w, &alpha[i*w->width] ) )
+ {
+ crop[0] = i;
+ break;
+ }
+ }
+
+ if( crop[0] < 0 )
+ {
+ /* Empty subtitle */
+ return NULL;
+ }
+
+ /* Bottom */
+ for( i = w->height - 1; i >= 0; i-- )
+ {
+ if( !LineIsTransparent( w, &alpha[i*w->width] ) )
+ {
+ crop[1] = i;
+ break;
+ }
+ }
+
+ /* Left */
+ for( i = 0; i < w->width; i++ )
+ {
+ if( !ColumnIsTransparent( w, &alpha[i] ) )
+ {
+ crop[2] = i;
+ break;
+ }
+ }
+
+ /* Right */
+ for( i = w->width - 1; i >= 0; i-- )
+ {
+ if( !ColumnIsTransparent( w, &alpha[i] ) )
+ {
+ crop[3] = i;
+ break;
+ }
+ }
+
+ realwidth = crop[3] - crop[2] + 1;
+ realheight = crop[1] - crop[0] + 1;
+
+ buf = hb_buffer_init( realwidth * realheight * 2 );
+ buf->start = w->pts_start;
+ buf->stop = w->pts_stop;
+ buf->x = w->x + crop[2];
+ buf->y = w->y + crop[0];
+ buf->width = realwidth;
+ buf->height = realheight;
+
+ lum_in = raw + crop[0] * w->width + crop[2];
+ alpha_in = lum_in + w->width * w->height;
+ lum_out = buf->data;
+ alpha_out = lum_out + realwidth * realheight;
+
+ for( i = 0; i < realheight; i++ )
+ {
+ memcpy( lum_out, lum_in, realwidth );
+ memcpy( alpha_out, alpha_in, realwidth );
+ lum_in += w->width;
+ alpha_in += w->width;
+ lum_out += realwidth;
+ alpha_out += realwidth;
+ }
+
+ return buf;
+}
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