yading@10: /*
yading@10:  * DVB subtitle encoding
yading@10:  * Copyright (c) 2005 Fabrice Bellard
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "libavutil/colorspace.h"
yading@10: 
yading@10: typedef struct DVBSubtitleContext {
yading@10:     int object_version;
yading@10: } DVBSubtitleContext;
yading@10: 
yading@10: #define PUTBITS2(val)\
yading@10: {\
yading@10:     bitbuf |= (val) << bitcnt;\
yading@10:     bitcnt -= 2;\
yading@10:     if (bitcnt < 0) {\
yading@10:         bitcnt = 6;\
yading@10:         *q++ = bitbuf;\
yading@10:         bitbuf = 0;\
yading@10:     }\
yading@10: }
yading@10: 
yading@10: static void dvb_encode_rle2(uint8_t **pq,
yading@10:                             const uint8_t *bitmap, int linesize,
yading@10:                             int w, int h)
yading@10: {
yading@10:     uint8_t *q;
yading@10:     unsigned int bitbuf;
yading@10:     int bitcnt;
yading@10:     int x, y, len, x1, v, color;
yading@10: 
yading@10:     q = *pq;
yading@10: 
yading@10:     for(y = 0; y < h; y++) {
yading@10:         *q++ = 0x10;
yading@10:         bitbuf = 0;
yading@10:         bitcnt = 6;
yading@10: 
yading@10:         x = 0;
yading@10:         while (x < w) {
yading@10:             x1 = x;
yading@10:             color = bitmap[x1++];
yading@10:             while (x1 < w && bitmap[x1] == color)
yading@10:                 x1++;
yading@10:             len = x1 - x;
yading@10:             if (color == 0 && len == 2) {
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(1);
yading@10:             } else if (len >= 3 && len <= 10) {
yading@10:                 v = len - 3;
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2((v >> 2) | 2);
yading@10:                 PUTBITS2(v & 3);
yading@10:                 PUTBITS2(color);
yading@10:             } else if (len >= 12 && len <= 27) {
yading@10:                 v = len - 12;
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(2);
yading@10:                 PUTBITS2(v >> 2);
yading@10:                 PUTBITS2(v & 3);
yading@10:                 PUTBITS2(color);
yading@10:             } else if (len >= 29) {
yading@10:                 /* length = 29 ... 284 */
yading@10:                 if (len > 284)
yading@10:                     len = 284;
yading@10:                 v = len - 29;
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(0);
yading@10:                 PUTBITS2(3);
yading@10:                 PUTBITS2((v >> 6));
yading@10:                 PUTBITS2((v >> 4) & 3);
yading@10:                 PUTBITS2((v >> 2) & 3);
yading@10:                 PUTBITS2(v & 3);
yading@10:                 PUTBITS2(color);
yading@10:             } else {
yading@10:                 PUTBITS2(color);
yading@10:                 if (color == 0) {
yading@10:                     PUTBITS2(1);
yading@10:                 }
yading@10:                 len = 1;
yading@10:             }
yading@10:             x += len;
yading@10:         }
yading@10:         /* end of line */
yading@10:         PUTBITS2(0);
yading@10:         PUTBITS2(0);
yading@10:         PUTBITS2(0);
yading@10:         if (bitcnt != 6) {
yading@10:             *q++ = bitbuf;
yading@10:         }
yading@10:         *q++ = 0xf0;
yading@10:         bitmap += linesize;
yading@10:     }
yading@10:     *pq = q;
yading@10: }
yading@10: 
yading@10: #define PUTBITS4(val)\
yading@10: {\
yading@10:     bitbuf |= (val) << bitcnt;\
yading@10:     bitcnt -= 4;\
yading@10:     if (bitcnt < 0) {\
yading@10:         bitcnt = 4;\
yading@10:         *q++ = bitbuf;\
yading@10:         bitbuf = 0;\
yading@10:     }\
yading@10: }
yading@10: 
yading@10: /* some DVB decoders only implement 4 bits/pixel */
yading@10: static void dvb_encode_rle4(uint8_t **pq,
yading@10:                             const uint8_t *bitmap, int linesize,
yading@10:                             int w, int h)
yading@10: {
yading@10:     uint8_t *q;
yading@10:     unsigned int bitbuf;
yading@10:     int bitcnt;
yading@10:     int x, y, len, x1, v, color;
yading@10: 
yading@10:     q = *pq;
yading@10: 
yading@10:     for(y = 0; y < h; y++) {
yading@10:         *q++ = 0x11;
yading@10:         bitbuf = 0;
yading@10:         bitcnt = 4;
yading@10: 
yading@10:         x = 0;
yading@10:         while (x < w) {
yading@10:             x1 = x;
yading@10:             color = bitmap[x1++];
yading@10:             while (x1 < w && bitmap[x1] == color)
yading@10:                 x1++;
yading@10:             len = x1 - x;
yading@10:             if (color == 0 && len == 2) {
yading@10:                 PUTBITS4(0);
yading@10:                 PUTBITS4(0xd);
yading@10:             } else if (color == 0 && (len >= 3 && len <= 9)) {
yading@10:                 PUTBITS4(0);
yading@10:                 PUTBITS4(len - 2);
yading@10:             } else if (len >= 4 && len <= 7) {
yading@10:                 PUTBITS4(0);
yading@10:                 PUTBITS4(8 + len - 4);
yading@10:                 PUTBITS4(color);
yading@10:             } else if (len >= 9 && len <= 24) {
yading@10:                 PUTBITS4(0);
yading@10:                 PUTBITS4(0xe);
yading@10:                 PUTBITS4(len - 9);
yading@10:                 PUTBITS4(color);
yading@10:             } else if (len >= 25) {
yading@10:                 if (len > 280)
yading@10:                     len = 280;
yading@10:                 v = len - 25;
yading@10:                 PUTBITS4(0);
yading@10:                 PUTBITS4(0xf);
yading@10:                 PUTBITS4(v >> 4);
yading@10:                 PUTBITS4(v & 0xf);
yading@10:                 PUTBITS4(color);
yading@10:             } else {
yading@10:                 PUTBITS4(color);
yading@10:                 if (color == 0) {
yading@10:                     PUTBITS4(0xc);
yading@10:                 }
yading@10:                 len = 1;
yading@10:             }
yading@10:             x += len;
yading@10:         }
yading@10:         /* end of line */
yading@10:         PUTBITS4(0);
yading@10:         PUTBITS4(0);
yading@10:         if (bitcnt != 4) {
yading@10:             *q++ = bitbuf;
yading@10:         }
yading@10:         *q++ = 0xf0;
yading@10:         bitmap += linesize;
yading@10:     }
yading@10:     *pq = q;
yading@10: }
yading@10: 
yading@10: static void dvb_encode_rle8(uint8_t **pq,
yading@10:                             const uint8_t *bitmap, int linesize,
yading@10:                             int w, int h)
yading@10: {
yading@10:     uint8_t *q;
yading@10:     int x, y, len, x1, color;
yading@10: 
yading@10:     q = *pq;
yading@10: 
yading@10:     for (y = 0; y < h; y++) {
yading@10:         *q++ = 0x12;
yading@10: 
yading@10:         x = 0;
yading@10:         while (x < w) {
yading@10:             x1 = x;
yading@10:             color = bitmap[x1++];
yading@10:             while (x1 < w && bitmap[x1] == color)
yading@10:                 x1++;
yading@10:             len = x1 - x;
yading@10:             if (len == 1 && color) {
yading@10:                 // 00000001 to 11111111           1 pixel in colour x
yading@10:                 *q++ = color;
yading@10:             } else {
yading@10:                 if (color == 0x00) {
yading@10:                     // 00000000 0LLLLLLL          L pixels (1-127) in colour 0 (L > 0)
yading@10:                     len = FFMIN(len, 127);
yading@10:                     *q++ = 0x00;
yading@10:                     *q++ = len;
yading@10:                 } else if (len > 2) {
yading@10:                     // 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2)
yading@10:                     len = FFMIN(len, 127);
yading@10:                     *q++ = 0x00;
yading@10:                     *q++ = 0x80+len;
yading@10:                     *q++ = color;
yading@10:                 }
yading@10:                 else if (len == 2) {
yading@10:                     *q++ = color;
yading@10:                     *q++ = color;
yading@10:                 } else {
yading@10:                     *q++ = color;
yading@10:                     len = 1;
yading@10:                 }
yading@10:             }
yading@10:             x += len;
yading@10:         }
yading@10:         /* end of line */
yading@10:         // 00000000 00000000 end of 8-bit/pixel_code_string
yading@10:         *q++ = 0x00;
yading@10:         *q++ = 0x00;
yading@10:         bitmap += linesize;
yading@10:     }
yading@10:     *pq = q;
yading@10: }
yading@10: 
yading@10: static int encode_dvb_subtitles(DVBSubtitleContext *s,
yading@10:                                 uint8_t *outbuf, const AVSubtitle *h)
yading@10: {
yading@10:     uint8_t *q, *pseg_len;
yading@10:     int page_id, region_id, clut_id, object_id, i, bpp_index, page_state;
yading@10: 
yading@10: 
yading@10:     q = outbuf;
yading@10: 
yading@10:     page_id = 1;
yading@10: 
yading@10:     if (h->num_rects && h->rects == NULL)
yading@10:         return -1;
yading@10: 
yading@10:     *q++ = 0x00; /* subtitle_stream_id */
yading@10: 
yading@10:     /* page composition segment */
yading@10: 
yading@10:     *q++ = 0x0f; /* sync_byte */
yading@10:     *q++ = 0x10; /* segment_type */
yading@10:     bytestream_put_be16(&q, page_id);
yading@10:     pseg_len = q;
yading@10:     q += 2; /* segment length */
yading@10:     *q++ = 30; /* page_timeout (seconds) */
yading@10:     page_state = 2; /* mode change */
yading@10:     /* page_version = 0 + page_state */
yading@10:     *q++ = (s->object_version << 4) | (page_state << 2) | 3;
yading@10: 
yading@10:     for (region_id = 0; region_id < h->num_rects; region_id++) {
yading@10:         *q++ = region_id;
yading@10:         *q++ = 0xff; /* reserved */
yading@10:         bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */
yading@10:         bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */
yading@10:     }
yading@10: 
yading@10:     bytestream_put_be16(&pseg_len, q - pseg_len - 2);
yading@10: 
yading@10:     if (h->num_rects) {
yading@10:         for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
yading@10: 
yading@10:             /* CLUT segment */
yading@10: 
yading@10:             if (h->rects[clut_id]->nb_colors <= 4) {
yading@10:                 /* 2 bpp, some decoders do not support it correctly */
yading@10:                 bpp_index = 0;
yading@10:             } else if (h->rects[clut_id]->nb_colors <= 16) {
yading@10:                 /* 4 bpp, standard encoding */
yading@10:                 bpp_index = 1;
yading@10:             } else if (h->rects[clut_id]->nb_colors <= 256) {
yading@10:                 /* 8 bpp, standard encoding */
yading@10:                 bpp_index = 2;
yading@10:             } else {
yading@10:                 return -1;
yading@10:             }
yading@10: 
yading@10: 
yading@10:             /* CLUT segment */
yading@10:             *q++ = 0x0f; /* sync byte */
yading@10:             *q++ = 0x12; /* CLUT definition segment */
yading@10:             bytestream_put_be16(&q, page_id);
yading@10:             pseg_len = q;
yading@10:             q += 2; /* segment length */
yading@10:             *q++ = clut_id;
yading@10:             *q++ = (0 << 4) | 0xf; /* version = 0 */
yading@10: 
yading@10:             for(i = 0; i < h->rects[clut_id]->nb_colors; i++) {
yading@10:                 *q++ = i; /* clut_entry_id */
yading@10:                 *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */
yading@10:                 {
yading@10:                     int a, r, g, b;
yading@10:                     uint32_t x= ((uint32_t*)h->rects[clut_id]->pict.data[1])[i];
yading@10:                     a = (x >> 24) & 0xff;
yading@10:                     r = (x >> 16) & 0xff;
yading@10:                     g = (x >>  8) & 0xff;
yading@10:                     b = (x >>  0) & 0xff;
yading@10: 
yading@10:                     *q++ = RGB_TO_Y_CCIR(r, g, b);
yading@10:                     *q++ = RGB_TO_V_CCIR(r, g, b, 0);
yading@10:                     *q++ = RGB_TO_U_CCIR(r, g, b, 0);
yading@10:                     *q++ = 255 - a;
yading@10:                 }
yading@10:             }
yading@10: 
yading@10:             bytestream_put_be16(&pseg_len, q - pseg_len - 2);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     for (region_id = 0; region_id < h->num_rects; region_id++) {
yading@10: 
yading@10:         /* region composition segment */
yading@10: 
yading@10:         if (h->rects[region_id]->nb_colors <= 4) {
yading@10:             /* 2 bpp, some decoders do not support it correctly */
yading@10:             bpp_index = 0;
yading@10:         } else if (h->rects[region_id]->nb_colors <= 16) {
yading@10:             /* 4 bpp, standard encoding */
yading@10:             bpp_index = 1;
yading@10:         } else {
yading@10:             return -1;
yading@10:         }
yading@10: 
yading@10:         *q++ = 0x0f; /* sync_byte */
yading@10:         *q++ = 0x11; /* segment_type */
yading@10:         bytestream_put_be16(&q, page_id);
yading@10:         pseg_len = q;
yading@10:         q += 2; /* segment length */
yading@10:         *q++ = region_id;
yading@10:         *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
yading@10:         bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */
yading@10:         bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */
yading@10:         *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03;
yading@10:         *q++ = region_id; /* clut_id == region_id */
yading@10:         *q++ = 0; /* 8 bit fill colors */
yading@10:         *q++ = 0x03; /* 4 bit and 2 bit fill colors */
yading@10: 
yading@10:         bytestream_put_be16(&q, region_id); /* object_id == region_id */
yading@10:         *q++ = (0 << 6) | (0 << 4);
yading@10:         *q++ = 0;
yading@10:         *q++ = 0xf0;
yading@10:         *q++ = 0;
yading@10: 
yading@10:         bytestream_put_be16(&pseg_len, q - pseg_len - 2);
yading@10:     }
yading@10: 
yading@10:     if (h->num_rects) {
yading@10: 
yading@10:         for (object_id = 0; object_id < h->num_rects; object_id++) {
yading@10:             void (*dvb_encode_rle)(uint8_t **pq,
yading@10:                                     const uint8_t *bitmap, int linesize,
yading@10:                                     int w, int h);
yading@10: 
yading@10:             /* bpp_index maths */
yading@10:             if (h->rects[object_id]->nb_colors <= 4) {
yading@10:                 /* 2 bpp, some decoders do not support it correctly */
yading@10:                 dvb_encode_rle = dvb_encode_rle2;
yading@10:             } else if (h->rects[object_id]->nb_colors <= 16) {
yading@10:                 /* 4 bpp, standard encoding */
yading@10:                 dvb_encode_rle = dvb_encode_rle4;
yading@10:             } else if (h->rects[object_id]->nb_colors <= 256) {
yading@10:                 /* 8 bpp, standard encoding */
yading@10:                 dvb_encode_rle = dvb_encode_rle8;
yading@10:             } else {
yading@10:                 return -1;
yading@10:             }
yading@10: 
yading@10:             /* Object Data segment */
yading@10:             *q++ = 0x0f; /* sync byte */
yading@10:             *q++ = 0x13;
yading@10:             bytestream_put_be16(&q, page_id);
yading@10:             pseg_len = q;
yading@10:             q += 2; /* segment length */
yading@10: 
yading@10:             bytestream_put_be16(&q, object_id);
yading@10:             *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
yading@10:                                                                        onject_coding_method,
yading@10:                                                                        non_modifying_color_flag */
yading@10:             {
yading@10:                 uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
yading@10: 
yading@10:                 ptop_field_len = q;
yading@10:                 q += 2;
yading@10:                 pbottom_field_len = q;
yading@10:                 q += 2;
yading@10: 
yading@10:                 top_ptr = q;
yading@10:                 dvb_encode_rle(&q, h->rects[object_id]->pict.data[0], h->rects[object_id]->w * 2,
yading@10:                                     h->rects[object_id]->w, h->rects[object_id]->h >> 1);
yading@10:                 bottom_ptr = q;
yading@10:                 dvb_encode_rle(&q, h->rects[object_id]->pict.data[0] + h->rects[object_id]->w,
yading@10:                                     h->rects[object_id]->w * 2, h->rects[object_id]->w,
yading@10:                                     h->rects[object_id]->h >> 1);
yading@10: 
yading@10:                 bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
yading@10:                 bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
yading@10:             }
yading@10: 
yading@10:             bytestream_put_be16(&pseg_len, q - pseg_len - 2);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     /* end of display set segment */
yading@10: 
yading@10:     *q++ = 0x0f; /* sync_byte */
yading@10:     *q++ = 0x80; /* segment_type */
yading@10:     bytestream_put_be16(&q, page_id);
yading@10:     pseg_len = q;
yading@10:     q += 2; /* segment length */
yading@10: 
yading@10:     bytestream_put_be16(&pseg_len, q - pseg_len - 2);
yading@10: 
yading@10:     *q++ = 0xff; /* end of PES data */
yading@10: 
yading@10:     s->object_version = (s->object_version + 1) & 0xf;
yading@10:     return q - outbuf;
yading@10: }
yading@10: 
yading@10: static int dvbsub_encode(AVCodecContext *avctx,
yading@10:                          unsigned char *buf, int buf_size,
yading@10:                          const AVSubtitle *sub)
yading@10: {
yading@10:     DVBSubtitleContext *s = avctx->priv_data;
yading@10:     int ret;
yading@10: 
yading@10:     ret = encode_dvb_subtitles(s, buf, sub);
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: AVCodec ff_dvbsub_encoder = {
yading@10:     .name           = "dvbsub",
yading@10:     .type           = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id             = AV_CODEC_ID_DVB_SUBTITLE,
yading@10:     .priv_data_size = sizeof(DVBSubtitleContext),
yading@10:     .encode_sub     = dvbsub_encode,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("DVB subtitles"),
yading@10: };