subtitle codec type support

Originally committed as revision 4346 to svn://svn.ffmpeg.org/ffmpeg/trunk

6 files changed, 933 insertions, 3 deletions

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 913a222bf4..9e38eefdc9 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -17,8 +17,8 @@ OBJS= bitstream.o utils.o mem.o allcodecs.o \
       ratecontrol.o adpcm.o eval.o error_resilience.o \
       fft.o mdct.o raw.o golomb.o cabac.o\
       dpcm.o adx.o rational.o faandct.o parser.o g726.o \
-      vp3dsp.o integer.o h264idct.o rangecoder.o pnm.o h263.o msmpeg4.o h263dec.o
-      
+      vp3dsp.o integer.o h264idct.o rangecoder.o pnm.o h263.o msmpeg4.o h263dec.o dvdsub.o dvbsub.o
+
 ifeq ($(CONFIG_AASC_DECODER),yes)
     OBJS+= aasc.o
 endif
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 6e4b6ca0d2..a0a7d7fc4e 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -551,6 +551,10 @@ PCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
 
 #undef PCM_CODEC
 
+    /* subtitles */ 
+    register_avcodec(&dvdsub_decoder);
+    register_avcodec(&dvbsub_encoder);
+
     /* parsers */ 
     av_register_codec_parser(&mpegvideo_parser);
     av_register_codec_parser(&mpeg4video_parser);
@@ -568,5 +572,6 @@ PCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
 #ifdef CONFIG_AC3
     av_register_codec_parser(&ac3_parser);
 #endif
+    av_register_codec_parser(&dvdsub_parser);
 }
 
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index d5e7f46dc7..2abb391657 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -17,7 +17,7 @@ extern "C" {
 
 #define FFMPEG_VERSION_INT     0x000409
 #define FFMPEG_VERSION         "0.4.9-pre1"
-#define LIBAVCODEC_BUILD       4755
+#define LIBAVCODEC_BUILD       4756
 
 #define LIBAVCODEC_VERSION_INT FFMPEG_VERSION_INT
 #define LIBAVCODEC_VERSION     FFMPEG_VERSION
@@ -175,6 +175,10 @@ enum CodecID {
     CODEC_ID_GSM,    
     
     CODEC_ID_OGGTHEORA= 0x16000, 
+
+    /* subtitle codecs */
+    CODEC_ID_DVD_SUBTITLE= 0x17000, 
+    CODEC_ID_DVB_SUBTITLE, 
     
     CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport
                          stream (only used by libavformat) */
@@ -188,6 +192,7 @@ enum CodecType {
     CODEC_TYPE_VIDEO,
     CODEC_TYPE_AUDIO,
     CODEC_TYPE_DATA,
+    CODEC_TYPE_SUBTITLE,
 };
 
 /**
@@ -1880,6 +1885,20 @@ typedef struct AVPaletteControl {
 
 } AVPaletteControl;
 
+typedef struct AVSubtitle {
+    uint16_t format; /* 0 = graphics */
+    uint16_t x;
+    uint16_t y;
+    uint16_t w;
+    uint16_t h;
+    uint16_t nb_colors;
+    uint32_t start_display_time; /* relative to packet pts, in ms */
+    uint32_t end_display_time; /* relative to packet pts, in ms */
+    int linesize;
+    uint32_t *rgba_palette;
+    uint8_t *bitmap;
+} AVSubtitle;
+
 extern AVCodec ac3_encoder;
 extern AVCodec mp2_encoder;
 extern AVCodec mp3lame_encoder;
@@ -2067,6 +2086,10 @@ extern AVCodec rawvideo_decoder;
 extern AVCodec ac3_decoder;
 extern AVCodec dts_decoder;
 
+/* subtitles */
+extern AVCodec dvdsub_decoder;
+extern AVCodec dvbsub_encoder;
+
 /* resample.c */
 
 struct ReSampleContext;
@@ -2204,6 +2227,9 @@ int avcodec_decode_audio(AVCodecContext *avctx, int16_t *samples,
 int avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture, 
                          int *got_picture_ptr,
                          uint8_t *buf, int buf_size);
+int avcodec_decode_subtitle(AVCodecContext *avctx, AVSubtitle *sub,
+                            int *got_sub_ptr,
+                            const uint8_t *buf, int buf_size);
 int avcodec_parse_frame(AVCodecContext *avctx, uint8_t **pdata, 
                         int *data_size_ptr,
                         uint8_t *buf, int buf_size);
@@ -2211,6 +2237,8 @@ int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                          const short *samples);
 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size, 
                          const AVFrame *pict);
+int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size, 
+                            const AVSubtitle *sub);
 
 int avcodec_close(AVCodecContext *avctx);
 
@@ -2310,6 +2338,7 @@ extern AVCodecParser mjpeg_parser;
 extern AVCodecParser pnm_parser;
 extern AVCodecParser mpegaudio_parser;
 extern AVCodecParser ac3_parser;
+extern AVCodecParser dvdsub_parser;
 
 /* memory */
 void *av_malloc(unsigned int size);
diff --git a/libavcodec/dvbsub.c b/libavcodec/dvbsub.c
new file mode 100644
index 0000000000..9b52848d98
--- /dev/null
+++ b/libavcodec/dvbsub.c
@@ -0,0 +1,407 @@
+/*
+ * DVB subtitle encoding for ffmpeg
+ * Copyright (c) 2005 Fabrice Bellard.
+ *
+ * This library 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 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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
+ */
+#include "avcodec.h"
+
+typedef struct DVBSubtitleContext {
+    int hide_state;
+    int object_version;
+} DVBSubtitleContext;
+
+#define PUTBITS2(val)\
+{\
+    bitbuf |= (val) << bitcnt;\
+    bitcnt -= 2;\
+    if (bitcnt < 0) {\
+        bitcnt = 6;\
+        *q++ = bitbuf;\
+        bitbuf = 0;\
+    }\
+}
+
+static void dvb_encode_rle2(uint8_t **pq,
+                            const uint8_t *bitmap, int linesize,
+                            int w, int h)
+{
+    uint8_t *q;
+    unsigned int bitbuf;
+    int bitcnt;
+    int x, y, len, x1, v, color;
+
+    q = *pq;
+    
+    for(y = 0; y < h; y++) {
+        *q++ = 0x10;
+        bitbuf = 0;
+        bitcnt = 6;
+        
+        x = 0;
+        while (x < w) {
+            x1 = x;
+            color = bitmap[x1++];
+            while (x1 < w && bitmap[x1] == color)
+                x1++;
+            len = x1 - x;
+            if (color == 0 && len == 2) {
+                PUTBITS2(0);
+                PUTBITS2(0);
+                PUTBITS2(1);
+            } else if (len >= 3 && len <= 10) {
+                v = len - 3;
+                PUTBITS2(0);
+                PUTBITS2((v >> 2) | 2);
+                PUTBITS2(v & 3);
+                PUTBITS2(color);
+            } else if (len >= 12 && len <= 27) {
+                v = len - 12;
+                PUTBITS2(0);
+                PUTBITS2(0);
+                PUTBITS2(2);
+                PUTBITS2(v >> 2);
+                PUTBITS2(v & 3);
+                PUTBITS2(color);
+            } else if (len >= 29) {
+                /* length = 29 ... 284 */
+                if (len > 284)
+                    len = 284;
+                v = len - 29;
+                PUTBITS2(0);
+                PUTBITS2(0);
+                PUTBITS2(3);
+                PUTBITS2((v >> 6));
+                PUTBITS2((v >> 4) & 3);
+                PUTBITS2((v >> 2) & 3);
+                PUTBITS2(v & 3);
+                PUTBITS2(color);
+            } else {
+                PUTBITS2(color);
+                if (color == 0) {
+                    PUTBITS2(1);
+                }
+                len = 1;
+            }
+            x += len;
+        }
+        /* end of line */
+        PUTBITS2(0);
+        PUTBITS2(0);
+        PUTBITS2(0);
+        if (bitcnt != 6) {
+            *q++ = bitbuf;
+        }
+        *q++ = 0xf0;
+        bitmap += linesize;
+    }
+    *pq = q;
+}
+
+#define PUTBITS4(val)\
+{\
+    bitbuf |= (val) << bitcnt;\
+    bitcnt -= 4;\
+    if (bitcnt < 0) {\
+        bitcnt = 4;\
+        *q++ = bitbuf;\
+        bitbuf = 0;\
+    }\
+}
+
+/* some DVB decoders only implement 4 bits/pixel */
+static void dvb_encode_rle4(uint8_t **pq,
+                            const uint8_t *bitmap, int linesize,
+                            int w, int h)
+{
+    uint8_t *q;
+    unsigned int bitbuf;
+    int bitcnt;
+    int x, y, len, x1, v, color;
+
+    q = *pq;
+    
+    for(y = 0; y < h; y++) {
+        *q++ = 0x11;
+        bitbuf = 0;
+        bitcnt = 4;
+        
+        x = 0;
+        while (x < w) {
+            x1 = x;
+            color = bitmap[x1++];
+            while (x1 < w && bitmap[x1] == color)
+                x1++;
+            len = x1 - x;
+            if (color == 0 && len == 2) {
+                PUTBITS4(0);
+                PUTBITS4(0xd);
+            } else if (color == 0 && (len >= 3 && len <= 9)) {
+                PUTBITS4(0);
+                PUTBITS4(len - 2);
+            } else if (len >= 4 && len <= 7) {
+                PUTBITS4(0);
+                PUTBITS4(8 + len - 4);
+                PUTBITS4(color);
+            } else if (len >= 9 && len <= 24) {
+                PUTBITS4(0);
+                PUTBITS4(0xe);
+                PUTBITS4(len - 9);
+                PUTBITS4(color);
+            } else if (len >= 25) {
+                if (len > 280)
+                    len = 280;
+                v = len - 25;
+                PUTBITS4(0);
+                PUTBITS4(0xf);
+                PUTBITS4(v >> 4);
+                PUTBITS4(v & 0xf);
+                PUTBITS4(color);
+            } else {
+                PUTBITS4(color);
+                if (color == 0) {
+                    PUTBITS4(0xc);
+                }
+                len = 1;
+            }
+            x += len;
+        }
+        /* end of line */
+        PUTBITS4(0);
+        PUTBITS4(0);
+        if (bitcnt != 4) {
+            *q++ = bitbuf;
+        }
+        *q++ = 0xf0;
+        bitmap += linesize;
+    }
+    *pq = q;
+}
+
+#define SCALEBITS 10
+#define ONE_HALF  (1 << (SCALEBITS - 1))
+#define FIX(x)	  ((int) ((x) * (1<<SCALEBITS) + 0.5))
+
+#define RGB_TO_Y_CCIR(r, g, b) \
+((FIX(0.29900*219.0/255.0) * (r) + FIX(0.58700*219.0/255.0) * (g) + \
+  FIX(0.11400*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
+
+#define RGB_TO_U_CCIR(r1, g1, b1, shift)\
+(((- FIX(0.16874*224.0/255.0) * r1 - FIX(0.33126*224.0/255.0) * g1 +         \
+     FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
+
+#define RGB_TO_V_CCIR(r1, g1, b1, shift)\
+(((FIX(0.50000*224.0/255.0) * r1 - FIX(0.41869*224.0/255.0) * g1 -           \
+   FIX(0.08131*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
+
+static inline void putbe16(uint8_t **pq, uint16_t v)
+{
+    uint8_t *q;
+    q = *pq;
+    *q++ = v >> 8;
+    *q++ = v;
+    *pq = q;
+}
+
+static int encode_dvb_subtitles(DVBSubtitleContext *s, 
+                                uint8_t *outbuf, AVSubtitle *h)
+{
+    uint8_t *q, *pseg_len;
+    int page_id, region_id, clut_id, object_id, i, bpp_index, page_state;
+
+
+    q = outbuf;
+
+    page_id = 1;
+    region_id = 0;
+    clut_id = 0;
+    object_id = 0;
+    if (h->nb_colors <= 4) {
+        /* 2 bpp, some decoders do not support it correctly */
+        bpp_index = 0;
+    } else if (h->nb_colors <= 16) {
+        /* 4 bpp, standard encoding */
+        bpp_index = 1;
+    } else {
+        return -1;
+    }
+
+    *q++ = 0x00; /* subtitle_stream_id */
+
+    /* page composition segment */
+
+    *q++ = 0x0f; /* sync_byte */
+    *q++ = 0x10; /* segment_type */
+    putbe16(&q, page_id);
+    pseg_len = q;
+    q += 2; /* segment length */
+    *q++ = 30; /* page_timeout (seconds) */
+    if (s->hide_state)
+        page_state = 0; /* normal case */
+    else
+        page_state = 2; /* mode change */
+    /* page_version = 0 + page_state */
+    *q++ = s->object_version | (page_state << 2) | 3; 
+    *q++ = region_id;
+    *q++ = 0xff; /* reserved */
+    putbe16(&q, 0); /* left pos */
+    putbe16(&q, 0); /* top pos */
+
+    putbe16(&pseg_len, q - pseg_len - 2);
+
+    if (!s->hide_state) {
+        /* CLUT segment */
+        
+        *q++ = 0x0f; /* sync byte */
+        *q++ = 0x12; /* CLUT definition segment */
+        putbe16(&q, page_id);
+        pseg_len = q;
+        q += 2; /* segment length */
+        *q++ = clut_id;
+        *q++ = (0 << 4) | 0xf; /* version = 0 */
+        
+        for(i = 0; i < h->nb_colors; i++) {
+            *q++ = i; /* clut_entry_id */
+            *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */
+            {
+                int a, r, g, b;
+                a = (h->rgba_palette[i] >> 24) & 0xff;
+                r = (h->rgba_palette[i] >> 16) & 0xff;
+                g = (h->rgba_palette[i] >> 8) & 0xff;
+                b = (h->rgba_palette[i] >> 0) & 0xff;
+                
+                *q++ = RGB_TO_Y_CCIR(r, g, b);
+                *q++ = RGB_TO_V_CCIR(r, g, b, 0);
+                *q++ = RGB_TO_U_CCIR(r, g, b, 0);
+                *q++ = 255 - a;
+            }
+        }
+
+        putbe16(&pseg_len, q - pseg_len - 2);
+    }
+    /* region composition segment */
+
+    *q++ = 0x0f; /* sync_byte */
+    *q++ = 0x11; /* segment_type */
+    putbe16(&q, page_id);
+    pseg_len = q;
+    q += 2; /* segment length */
+    *q++ = region_id;
+    *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
+    putbe16(&q, 720); /* region width */
+    putbe16(&q, 576); /* region height */
+    *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03; 
+    *q++ = clut_id;
+    *q++ = 0; /* 8 bit fill colors */
+    *q++ = 0x03; /* 4 bit and 2 bit fill colors */
+    
+    if (!s->hide_state) {
+        putbe16(&q, object_id);
+        *q++ = (0 << 6) | (0 << 4) | ((h->x >> 8) & 0xf);  
+        *q++ = h->x;
+        *q++ = 0xf0 | ((h->y >> 8) & 0xf);
+        *q++ = h->y;
+    }
+    
+    putbe16(&pseg_len, q - pseg_len - 2);
+
+    if (!s->hide_state) {
+        
+    /* Object Data segment */
+
+    *q++ = 0x0f; /* sync byte */
+    *q++ = 0x13;
+    putbe16(&q, page_id);
+    pseg_len = q;
+    q += 2; /* segment length */
+    
+    putbe16(&q, object_id);
+    *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
+                                                               onject_coding_method,
+                                                               non_modifying_color_flag */
+    {
+        uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
+        void (*dvb_encode_rle)(uint8_t **pq,
+                                const uint8_t *bitmap, int linesize,
+                                int w, int h);
+        ptop_field_len = q;
+        q += 2;
+        pbottom_field_len = q;
+        q += 2;
+
+        if (bpp_index == 0)
+            dvb_encode_rle = dvb_encode_rle2;
+        else
+            dvb_encode_rle = dvb_encode_rle4;
+            
+        top_ptr = q;
+        dvb_encode_rle(&q, h->bitmap, h->w * 2, h->w, h->h >> 1);
+        bottom_ptr = q;
+        dvb_encode_rle(&q, h->bitmap + h->w, h->w * 2, h->w, h->h >> 1);
+
+        putbe16(&ptop_field_len, bottom_ptr - top_ptr);
+        putbe16(&pbottom_field_len, q - bottom_ptr);
+    }
+
+    putbe16(&pseg_len, q - pseg_len - 2);
+    }
+
+    /* end of display set segment */
+
+    *q++ = 0x0f; /* sync_byte */
+    *q++ = 0x80; /* segment_type */
+    putbe16(&q, page_id);
+    pseg_len = q;
+    q += 2; /* segment length */
+
+    putbe16(&pseg_len, q - pseg_len - 2);
+
+    *q++ = 0xff; /* end of PES data */
+
+    s->object_version = (s->object_version + 1) & 0xf;
+    s->hide_state = !s->hide_state;
+    return q - outbuf;
+}
+
+static int dvbsub_init_decoder(AVCodecContext *avctx)
+{
+    return 0;
+}
+
+static int dvbsub_close_decoder(AVCodecContext *avctx)
+{
+    return 0;
+}
+
+static int dvbsub_encode(AVCodecContext *avctx,
+                       unsigned char *buf, int buf_size, void *data)
+{
+    DVBSubtitleContext *s = avctx->priv_data;
+    AVSubtitle *sub = data;
+    int ret;
+
+    ret = encode_dvb_subtitles(s, buf, sub);
+    return ret;
+}
+
+AVCodec dvbsub_encoder = {
+    "dvbsub",
+    CODEC_TYPE_SUBTITLE,
+    CODEC_ID_DVB_SUBTITLE,
+    sizeof(DVBSubtitleContext),
+    dvbsub_init_decoder,
+    dvbsub_encode,
+    dvbsub_close_decoder,
+};
diff --git a/libavcodec/dvdsub.c b/libavcodec/dvdsub.c
new file mode 100644
index 0000000000..af5d9aca02
--- /dev/null
+++ b/libavcodec/dvdsub.c
@@ -0,0 +1,459 @@
+/*
+ * DVD subtitle decoding for ffmpeg
+ * Copyright (c) 2005 Fabrice Bellard.
+ *
+ * This library 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 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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
+ */
+#include "avcodec.h"
+
+//#define DEBUG
+
+typedef struct DVDSubContext {
+} DVDSubContext;
+
+static int dvdsub_init_decoder(AVCodecContext *avctx)
+{
+    return 0;
+}
+
+uint16_t getbe16(const uint8_t *p)
+{
+    return (p[0] << 8) | p[1];
+}
+
+int get_nibble(const uint8_t *buf, int nibble_offset)
+{
+    return (buf[nibble_offset >> 1] >> ((1 - (nibble_offset & 1)) << 2)) & 0xf;
+}
+
+static int decode_rle(uint8_t *bitmap, int linesize, int w, int h, 
+                      const uint8_t *buf, int nibble_offset, int buf_size)
+{
+    unsigned int v;
+    int x, y, len, color, nibble_end;
+    uint8_t *d;
+
+    nibble_end = buf_size * 2;
+    x = 0;
+    y = 0;
+    d = bitmap;
+    for(;;) {
+        if (nibble_offset >= nibble_end)
+            return -1;
+        v = get_nibble(buf, nibble_offset++);
+        if (v < 0x4) {
+            v = (v << 4) | get_nibble(buf, nibble_offset++);
+            if (v < 0x10) {
+                v = (v << 4) | get_nibble(buf, nibble_offset++);
+                if (v < 0x040) {
+                    v = (v << 4) | get_nibble(buf, nibble_offset++);
+                    if (v < 4) {
+                        v |= (w - x) << 2;
+                    }
+                }
+            }
+        }
+        len = v >> 2;
+        if (len > (w - x))
+            len = (w - x);
+        color = v & 0x03;
+        memset(d + x, color, len);
+        x += len;
+        if (x >= w) {
+            y++;
+            if (y >= h)
+                break;
+            d += linesize;
+            x = 0;
+            /* byte align */
+            nibble_offset += (nibble_offset & 1);
+        }
+    }
+    return 0;
+}
+
+static void guess_palette(uint32_t *rgba_palette,
+                          uint8_t *palette,
+                          uint8_t *alpha,
+                          uint32_t subtitle_color)
+{
+    uint8_t color_used[16];
+    int nb_opaque_colors, i, level, j, r, g, b;
+    
+    for(i = 0; i < 4; i++)
+        rgba_palette[i] = 0;
+
+    memset(color_used, 0, 16);
+    nb_opaque_colors = 0;
+    for(i = 0; i < 4; i++) {
+        if (alpha[i] != 0 && !color_used[palette[i]]) {
+            color_used[palette[i]] = 1;
+            nb_opaque_colors++;
+        }
+    }
+    
+    if (nb_opaque_colors == 0)
+        return;
+    
+    j = 0;
+    memset(color_used, 0, 16);
+    for(i = 0; i < 4; i++) {
+        if (alpha[i] != 0) {
+            if (!color_used[palette[i]])  {
+                level = (0xff * (j + 1)) / nb_opaque_colors;
+                r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
+                g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
+                b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
+                rgba_palette[i] = b | (g << 8) | (r << 16) | (0xff << 24);
+                color_used[palette[i]] = (i + 1);
+                j++;
+            } else {
+                rgba_palette[i] = rgba_palette[color_used[palette[i]] - 1];
+            }
+        }
+    }
+}
+
+static int decode_dvd_subtitles(AVSubtitle *sub_header, 
+                                const uint8_t *buf, int buf_size)
+{
+    int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
+    uint8_t palette[4], alpha[4];
+    int date;
+    
+    if (buf_size < 4)
+        return -1;
+    sub_header->bitmap = NULL;
+    sub_header->rgba_palette = NULL;
+    sub_header->start_display_time = 0;
+    sub_header->end_display_time = 0;
+
+    cmd_pos = getbe16(buf + 2);
+    while ((cmd_pos + 4) < buf_size) {
+        date = getbe16(buf + cmd_pos);
+        next_cmd_pos = getbe16(buf + cmd_pos + 2);
+#ifdef DEBUG
+        av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n", 
+               cmd_pos, next_cmd_pos, date);
+#endif
+        pos = cmd_pos + 4;
+        offset1 = -1;
+        offset2 = -1;
+        x1 = y1 = x2 = y2 = 0;
+        while (pos < buf_size) {
+            cmd = buf[pos++];
+#ifdef DEBUG
+            av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd);
+#endif
+            switch(cmd) {
+            case 0x00:
+                /* force display */
+                break;
+            case 0x01:
+                /* set start date */
+                sub_header->start_display_time = date * 10;
+                break;
+            case 0x02:
+                /* set end date */
+                sub_header->end_display_time = date * 10;
+                break;
+            case 0x03:
+                /* set palette */
+                if ((buf_size - pos) < 2)
+                    goto fail;
+                palette[0] = buf[pos] >> 4;
+                palette[1] = buf[pos] & 0x0f;
+                palette[2] = buf[pos + 1] >> 4;
+                palette[3] = buf[pos + 1] & 0x0f;
+                pos += 2;
+                break;
+            case 0x04:
+                /* set alpha */
+                if ((buf_size - pos) < 2)
+                    goto fail;
+                alpha[0] = buf[pos] >> 4;
+                alpha[1] = buf[pos] & 0x0f;
+                alpha[2] = buf[pos + 1] >> 4;
+                alpha[3] = buf[pos + 1] & 0x0f;
+                pos += 2;
+                break;
+            case 0x05:
+                if ((buf_size - pos) < 6)
+                    goto fail;
+                x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
+                x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
+                y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
+                y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
+#ifdef DEBUG
+                av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n",
+                       x1, x2, y1, y2);
+#endif
+                pos += 6;
+                break;
+            case 0x06:
+                if ((buf_size - pos) < 4)
+                    goto fail;
+                offset1 = getbe16(buf + pos);
+                offset2 = getbe16(buf + pos + 2);
+#ifdef DEBUG
+                av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
+#endif
+                pos += 4;
+                break;
+            case 0xff:
+            default:
+                goto the_end;
+            }
+        }
+    the_end:
+        if (offset1 >= 0) {
+            int w, h;
+            uint8_t *bitmap;
+            
+            /* decode the bitmap */
+            w = x2 - x1 + 1;
+            if (w < 0)
+                w = 0;
+            h = y2 - y1;
+            if (h < 0)
+                h = 0;
+            if (w > 0 && h > 0) {
+                av_freep(&sub_header->bitmap);
+                av_freep(&sub_header->rgba_palette);
+                bitmap = av_malloc(w * h);
+                sub_header->rgba_palette = av_malloc(4 * 4);
+                decode_rle(bitmap, w * 2, w, h / 2,
+                           buf, offset1 * 2, buf_size);
+                decode_rle(bitmap + w, w * 2, w, h / 2,
+                           buf, offset2 * 2, buf_size);
+                guess_palette(sub_header->rgba_palette, 
+                              palette, alpha, 0xffff00);
+                sub_header->x = x1;
+                sub_header->y = y1;
+                sub_header->w = w;
+                sub_header->h = h;
+                sub_header->nb_colors = 4;
+                sub_header->linesize = w;
+                sub_header->bitmap = bitmap;
+            }
+        }
+        if (next_cmd_pos == cmd_pos)
+            break;
+        cmd_pos = next_cmd_pos;
+    }
+    if (sub_header->bitmap)
+        return 0;
+ fail:
+    return -1;
+}
+
+static int is_transp(const uint8_t *buf, int pitch, int n, 
+                     const uint8_t *transp_color)
+{
+    int i;
+    for(i = 0; i < n; i++) {
+        if (!transp_color[*buf])
+            return 0;
+        buf += pitch;
+    }
+    return 1;
+}
+
+/* return 0 if empty rectangle, 1 if non empty */
+static int find_smallest_bouding_rectangle(AVSubtitle *s)
+{
+    uint8_t transp_color[256];
+    int y1, y2, x1, x2, y, w, h, i;
+    uint8_t *bitmap;
+
+    if (s->w <= 0 || s->h <= 0)
+        return 0;
+
+    memset(transp_color, 0, 256);
+    for(i = 0; i < s->nb_colors; i++) {
+        if ((s->rgba_palette[i] >> 24) == 0)
+            transp_color[i] = 1;
+    }
+    y1 = 0;
+    while (y1 < s->h && is_transp(s->bitmap + y1 * s->linesize, 1, s->w, 
+                                  transp_color))
+        y1++;
+    if (y1 == s->h) {
+        av_freep(&s->bitmap);
+        s->w = s->h = 0;
+        return 0;
+    }
+
+    y2 = s->h - 1;
+    while (y2 > 0 && is_transp(s->bitmap + y2 * s->linesize, 1, s->w, 
+                               transp_color))
+        y2--;
+    x1 = 0;
+    while (x1 < (s->w - 1) && is_transp(s->bitmap + x1, s->linesize, s->h, 
+                                        transp_color))
+        x1++;
+    x2 = s->w - 1;
+    while (x2 > 0 && is_transp(s->bitmap + x2, s->linesize, s->h, 
+                                  transp_color))
+        x2--;
+    w = x2 - x1 + 1;
+    h = y2 - y1 + 1;
+    bitmap = av_malloc(w * h);
+    if (!bitmap)
+        return 1;
+    for(y = 0; y < h; y++) {
+        memcpy(bitmap + w * y, s->bitmap + x1 + (y1 + y) * s->linesize, w);
+    }
+    av_freep(&s->bitmap);
+    s->bitmap = bitmap;
+    s->linesize = w;
+    s->w = w;
+    s->h = h;
+    s->x += x1;
+    s->y += y1;
+    return 1;
+}
+
+static int dvdsub_close_decoder(AVCodecContext *avctx)
+{
+    return 0;
+}
+
+#ifdef DEBUG
+#undef fprintf
+static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
+                     uint32_t *rgba_palette)
+{
+    int x, y, v;
+    FILE *f;
+
+    f = fopen(filename, "w");
+    if (!f) {
+        perror(filename);
+        exit(1);
+    }
+    fprintf(f, "P6\n"
+            "%d %d\n"
+            "%d\n",
+            w, h, 255);
+    for(y = 0; y < h; y++) {
+        for(x = 0; x < w; x++) {
+            v = rgba_palette[bitmap[y * w + x]];
+            putc((v >> 16) & 0xff, f);
+            putc((v >> 8) & 0xff, f);
+            putc((v >> 0) & 0xff, f);
+        }
+    }
+    fclose(f);
+}
+#endif
+
+static int dvdsub_decode(AVCodecContext *avctx,
+                         void *data, int *data_size,
+                         uint8_t *buf, int buf_size)
+{
+    AVSubtitle *sub = (void *)data;
+
+    if (decode_dvd_subtitles(sub, buf, buf_size) < 0) {
+    no_subtitle:
+        *data_size = 0;
+
+        return buf_size;
+    }
+    if (find_smallest_bouding_rectangle(sub) == 0)
+        goto no_subtitle;
+
+#if defined(DEBUG)
+    av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n", 
+           sub->start_display_time,
+           sub->end_display_time);
+    ppm_save("/tmp/a.ppm", sub->bitmap, 
+             sub->w, sub->h, sub->rgba_palette);
+#endif
+
+    *data_size = 1;
+    return buf_size;
+}
+
+AVCodec dvdsub_decoder = {
+    "dvdsub",
+    CODEC_TYPE_SUBTITLE,
+    CODEC_ID_DVD_SUBTITLE,
+    sizeof(DVDSubContext),
+    dvdsub_init_decoder,
+    NULL,
+    dvdsub_close_decoder,
+    dvdsub_decode,
+};
+
+/* parser definition */
+typedef struct DVDSubParseContext {
+    uint8_t *packet;
+    int packet_len;
+    int packet_index;
+} DVDSubParseContext;
+
+static int dvdsub_parse_init(AVCodecParserContext *s)
+{
+    return 0;
+}
+
+static int dvdsub_parse(AVCodecParserContext *s,
+                        AVCodecContext *avctx,
+                        uint8_t **poutbuf, int *poutbuf_size, 
+                        const uint8_t *buf, int buf_size)
+{
+    DVDSubParseContext *pc = s->priv_data;
+    
+    if (pc->packet_index == 0) {
+        if (buf_size < 2)
+            return 0;
+        pc->packet_len = (buf[0] << 8) | buf[1];
+        av_freep(&pc->packet);
+        pc->packet = av_malloc(pc->packet_len);
+    }
+    if (pc->packet) {
+        if (pc->packet_index + buf_size <= pc->packet_len) {
+            memcpy(pc->packet + pc->packet_index, buf, buf_size);
+            pc->packet_index += buf_size;
+            if (pc->packet_index >= pc->packet_len) {
+                *poutbuf = pc->packet;
+                *poutbuf_size = pc->packet_len;
+                pc->packet_index = 0;
+                return buf_size;
+            }
+        } else {
+            /* erroneous size */
+            pc->packet_index = 0;
+        }
+    }
+    *poutbuf = NULL;
+    *poutbuf_size = 0;
+    return buf_size;
+}
+
+static void dvdsub_parse_close(AVCodecParserContext *s)
+{
+    DVDSubParseContext *pc = s->priv_data;
+    av_freep(&pc->packet);
+}
+
+AVCodecParser dvdsub_parser = {
+    { CODEC_ID_DVD_SUBTITLE },
+    sizeof(DVDSubParseContext),
+    dvdsub_parse_init,
+    dvdsub_parse,
+    dvdsub_parse_close,
+};
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index d1debfe402..a964a6fd46 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -590,6 +590,15 @@ int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
         return 0;
 }
 
+int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size, 
+                            const AVSubtitle *sub)
+{
+    int ret;
+    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)sub);
+    avctx->frame_number++;
+    return ret;
+}
+
 /** 
  * decode a frame. 
  * @param buf bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE larger then the actual read bytes
@@ -639,6 +648,23 @@ int avcodec_decode_audio(AVCodecContext *avctx, int16_t *samples,
     return ret;
 }
 
+/* decode a subtitle message. return -1 if error, otherwise return the
+   *number of bytes used. If no subtitle could be decompressed,
+   *got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */
+int avcodec_decode_subtitle(AVCodecContext *avctx, AVSubtitle *sub,
+                            int *got_sub_ptr,
+                            const uint8_t *buf, int buf_size)
+{
+    int ret;
+
+    *got_sub_ptr = 0;
+    ret = avctx->codec->decode(avctx, sub, got_sub_ptr, 
+                               (uint8_t *)buf, buf_size);
+    if (*got_sub_ptr)
+        avctx->frame_number++;
+    return ret;
+}
+
 int avcodec_close(AVCodecContext *avctx)
 {
     if (avctx->codec->close)
@@ -808,6 +834,10 @@ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
         snprintf(buf, buf_size, "Data: %s", codec_name);
         bitrate = enc->bit_rate;
         break;
+    case CODEC_TYPE_SUBTITLE:
+        snprintf(buf, buf_size, "Subtitle: %s", codec_name);
+        bitrate = enc->bit_rate;
+        break;
     default:
         snprintf(buf, buf_size, "Invalid Codec type %d", enc->codec_type);
         return;