/src/ffmpeg/libavcodec/dvbsubenc.c

Source
/*
 * DVB subtitle encoding
 * Copyright (c) 2005 Fabrice Bellard
 *
 * 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 "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "libavutil/colorspace.h"
#include "libavutil/opt.h"

typedef struct DVBSubtitleContext {
    AVClass * class;
    int object_version;
    int min_bpp;
} DVBSubtitleContext;

#define PUTBITS2(val)\
{\
    bitbuf |= (val) << bitcnt;\
    bitcnt -= 2;\
    if (bitcnt < 0) {\
        bitcnt = 6;\
        *q++ = bitbuf;\
        bitbuf = 0;\
    }\
}

static int dvb_encode_rle2(uint8_t **pq, int buf_size,
                           const uint8_t *bitmap, int linesize,
                           int w, int h)
{
    uint8_t *q, *line_begin;
    unsigned int bitbuf;
    int bitcnt;
    int x, y, len, x1, v, color;

    q = *pq;

    for(y = 0; y < h; y++) {
        // Worst case line is 3 bits per value + 4 bytes overhead
        if (buf_size * 8 < w * 3 + 32)
            return AVERROR_BUFFER_TOO_SMALL;
        line_begin = q;
        *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;
        buf_size -= q - line_begin;
    }
    len = q - *pq;
    *pq = q;
    return len;
}

#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 int dvb_encode_rle4(uint8_t **pq, int buf_size,
                           const uint8_t *bitmap, int linesize,
                           int w, int h)
{
    uint8_t *q, *line_begin;
    unsigned int bitbuf;
    int bitcnt;
    int x, y, len, x1, v, color;

    q = *pq;

    for(y = 0; y < h; y++) {
        // Worst case line is 6 bits per value, + 4 bytes overhead
        if (buf_size * 8 < w * 6 + 32)
            return AVERROR_BUFFER_TOO_SMALL;
        line_begin = q;
        *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;
        buf_size -= q - line_begin;
    }
    len = q - *pq;
    *pq = q;
    return len;
}

static int dvb_encode_rle8(uint8_t **pq, int buf_size,
                           const uint8_t *bitmap, int linesize,
                           int w, int h)
{
    uint8_t *q, *line_begin;
    int x, y, len, x1, color;

    q = *pq;

    for (y = 0; y < h; y++) {
        // Worst case line is 12 bits per value, + 3 bytes overhead
        if (buf_size * 8 < w * 12 + 24)
            return AVERROR_BUFFER_TOO_SMALL;
        line_begin = q;
        *q++ = 0x12;

        x = 0;
        while (x < w) {
            x1 = x;
            color = bitmap[x1++];
            while (x1 < w && bitmap[x1] == color)
                x1++;
            len = x1 - x;
            if (len == 1 && color) {
                // 00000001 to 11111111           1 pixel in colour x
                *q++ = color;
            } else {
                if (color == 0x00) {
                    // 00000000 0LLLLLLL          L pixels (1-127) in colour 0 (L > 0)
                    len = FFMIN(len, 127);
                    *q++ = 0x00;
                    *q++ = len;
                } else if (len > 2) {
                    // 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2)
                    len = FFMIN(len, 127);
                    *q++ = 0x00;
                    *q++ = 0x80+len;
                    *q++ = color;
                }
                else if (len == 2) {
                    *q++ = color;
                    *q++ = color;
                } else {
                    *q++ = color;
                    len = 1;
                }
            }
            x += len;
        }
        /* end of line */
        // 00000000 00000000 end of 8-bit/pixel_code_string
        *q++ = 0x00;
        *q++ = 0x00;
        *q++ = 0xf0;
        bitmap += linesize;
        buf_size -= q - line_begin;
    }
    len = q - *pq;
    *pq = q;
    return len;
}

static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size,
                         const AVSubtitle *h)
{
    DVBSubtitleContext *s = avctx->priv_data;
    uint8_t *q, *pseg_len;
    int page_id, region_id, clut_id, object_id, i, bpp_index, page_state, min_colors;


    q = outbuf;

    page_id = 1;

    switch(s->min_bpp) {
    case 2:
    case 4:
    case 8:
      min_colors = 1 << s->min_bpp;
      break;
    default:
      av_log(avctx, AV_LOG_ERROR, "Invalid min_bpp value %d.\n", s->min_bpp);
      return AVERROR(EINVAL);
    }

    if (h->num_rects && !h->rects)
        return AVERROR(EINVAL);

    if (h->num_rects >= 256)
        return AVERROR(EINVAL);

    if (avctx->width > 0 && avctx->height > 0) {
        if (buf_size < 11)
            return AVERROR_BUFFER_TOO_SMALL;
        /* display definition segment */
        *q++ = 0x0f; /* sync_byte */
        *q++ = 0x14; /* segment_type */
        bytestream_put_be16(&q, page_id);
        pseg_len = q;
        q += 2; /* segment length */
        *q++ = 0x00; /* dds version number & display window flag */
        bytestream_put_be16(&q, avctx->width - 1); /* display width */
        bytestream_put_be16(&q, avctx->height - 1); /* display height */
        bytestream_put_be16(&pseg_len, q - pseg_len - 2);
        buf_size -= 11;
    }

    /* page composition segment */

    if (buf_size < 8 + h->num_rects * 6)
        return AVERROR_BUFFER_TOO_SMALL;
    *q++ = 0x0f; /* sync_byte */
    *q++ = 0x10; /* segment_type */
    bytestream_put_be16(&q, page_id);
    pseg_len = q;
    q += 2; /* segment length */
    *q++ = 30; /* page_timeout (seconds) */
    page_state = 2; /* mode change */
    /* page_version = 0 + page_state */
    *q++ = (s->object_version << 4) | (page_state << 2) | 3;

    for (region_id = 0; region_id < h->num_rects; region_id++) {
        *q++ = region_id;
        *q++ = 0xff; /* reserved */
        bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */
        bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */
    }

    bytestream_put_be16(&pseg_len, q - pseg_len - 2);
    buf_size -= 8 + h->num_rects * 6;

    if (h->num_rects) {
        for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
            /* CLUT segment */
            int nb_colors = FFMAX(min_colors, h->rects[clut_id]->nb_colors);

            if (nb_colors <= 4U) {
                /* 2 bpp, some decoders do not support it correctly */
                bpp_index = 0;
            } else if (nb_colors <= 16U) {
                /* 4 bpp, standard encoding */
                bpp_index = 1;
            } else if (nb_colors <= 256U) {
                /* 8 bpp, standard encoding */
                bpp_index = 2;
            } else {
                return AVERROR(EINVAL);
            }

            if (buf_size < 6 + h->rects[clut_id]->nb_colors * 6)
                return AVERROR_BUFFER_TOO_SMALL;

            /* CLUT segment */
            *q++ = 0x0f; /* sync byte */
            *q++ = 0x12; /* CLUT definition segment */
            bytestream_put_be16(&q, page_id);
            pseg_len = q;
            q += 2; /* segment length */
            *q++ = clut_id;
            *q++ = (0 << 4) | 0xf; /* version = 0 */

            for(i = 0; i < h->rects[clut_id]->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;
                    uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i];
                    a = (x >> 24) & 0xff;
                    r = (x >> 16) & 0xff;
                    g = (x >>  8) & 0xff;
                    b = (x >>  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;
                }
            }

            bytestream_put_be16(&pseg_len, q - pseg_len - 2);
            buf_size -= 6 + h->rects[clut_id]->nb_colors * 6;
        }

        if (buf_size < h->num_rects * 22)
            return AVERROR_BUFFER_TOO_SMALL;
        for (region_id = 0; region_id < h->num_rects; region_id++) {

            /* region composition segment */
            int nb_colors = FFMAX(min_colors, h->rects[region_id]->nb_colors);

            if (nb_colors <= 4) {
                /* 2 bpp, some decoders do not support it correctly */
                bpp_index = 0;
            } else if (nb_colors <= 16) {
                /* 4 bpp, standard encoding */
                bpp_index = 1;
            } else if (nb_colors <= 256) {
                /* 8 bpp, standard encoding */
                bpp_index = 2;
            } else {
                return AVERROR(EINVAL);
            }

            *q++ = 0x0f; /* sync_byte */
            *q++ = 0x11; /* segment_type */
            bytestream_put_be16(&q, page_id);
            pseg_len = q;
            q += 2; /* segment length */
            *q++ = region_id;
            *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
            bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */
            bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */
            *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03;
            *q++ = region_id; /* clut_id == region_id */
            *q++ = 0; /* 8 bit fill colors */
            *q++ = 0x03; /* 4 bit and 2 bit fill colors */

            bytestream_put_be16(&q, region_id); /* object_id == region_id */
            *q++ = (0 << 6) | (0 << 4);
            *q++ = 0;
            *q++ = 0xf0;
            *q++ = 0;

            bytestream_put_be16(&pseg_len, q - pseg_len - 2);
        }
        buf_size -= h->num_rects * 22;

        for (object_id = 0; object_id < h->num_rects; object_id++) {
            int (*dvb_encode_rle)(uint8_t **pq, int buf_size,
                                  const uint8_t *bitmap, int linesize,
                                  int w, int h);

            int nb_colors = FFMAX(min_colors, h->rects[object_id]->nb_colors);

            if (buf_size < 13)
                return AVERROR_BUFFER_TOO_SMALL;

            /* bpp_index maths */
            if (nb_colors <= 4) {
                /* 2 bpp, some decoders do not support it correctly */
                dvb_encode_rle = dvb_encode_rle2;
            } else if (nb_colors <= 16) {
                /* 4 bpp, standard encoding */
                dvb_encode_rle = dvb_encode_rle4;
            } else if (nb_colors <= 256) {
                /* 8 bpp, standard encoding */
                dvb_encode_rle = dvb_encode_rle8;
            } else {
                return AVERROR(EINVAL);
            }

            /* Object Data segment */
            *q++ = 0x0f; /* sync byte */
            *q++ = 0x13;
            bytestream_put_be16(&q, page_id);
            pseg_len = q;
            q += 2; /* segment length */

            bytestream_put_be16(&q, object_id);
            *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
                                                                       object_coding_method,
                                                                       non_modifying_color_flag */
            {
                uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
                int ret;

                ptop_field_len = q;
                q += 2;
                pbottom_field_len = q;
                q += 2;
                buf_size -= 13;

                top_ptr = q;
                ret = dvb_encode_rle(&q, buf_size,
                                     h->rects[object_id]->data[0],
                                     h->rects[object_id]->w * 2,
                                     h->rects[object_id]->w,
                                     h->rects[object_id]->h >> 1);
                if (ret < 0)
                    return ret;
                buf_size -= ret;
                bottom_ptr = q;
                ret = dvb_encode_rle(&q, buf_size,
                                     h->rects[object_id]->data[0] + h->rects[object_id]->w,
                                     h->rects[object_id]->w * 2,
                                     h->rects[object_id]->w,
                                     h->rects[object_id]->h >> 1);
                if (ret < 0)
                    return ret;
                buf_size -= ret;

                bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
                bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
            }

            bytestream_put_be16(&pseg_len, q - pseg_len - 2);
        }
    }

    /* end of display set segment */

    if (buf_size < 6)
        return AVERROR_BUFFER_TOO_SMALL;
    *q++ = 0x0f; /* sync_byte */
    *q++ = 0x80; /* segment_type */
    bytestream_put_be16(&q, page_id);
    pseg_len = q;
    q += 2; /* segment length */

    bytestream_put_be16(&pseg_len, q - pseg_len - 2);
    buf_size -= 6;

    s->object_version = (s->object_version + 1) & 0xf;
    return q - outbuf;
}

#define OFFSET(x) offsetof(DVBSubtitleContext, x)
#define SE AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    {"min_bpp", "minimum bits-per-pixel for subtitle colors (2, 4 or 8)", OFFSET(min_bpp), AV_OPT_TYPE_INT, {.i64 = 4}, 2, 8, SE},
    { NULL },
};

static const AVClass dvbsubenc_class = {
    .class_name = "DVBSUB subtitle encoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

const FFCodec ff_dvbsub_encoder = {
    .p.name         = "dvbsub",
    CODEC_LONG_NAME("DVB subtitles"),
    .p.type         = AVMEDIA_TYPE_SUBTITLE,
    .p.id           = AV_CODEC_ID_DVB_SUBTITLE,
    .priv_data_size = sizeof(DVBSubtitleContext),
    FF_CODEC_ENCODE_SUB_CB(dvbsub_encode),
    .p.priv_class   = &dvbsubenc_class,
};

Coverage Report

Created: 2026-04-01 07:42

Line	Count	Source
1		/*
2		* DVB subtitle encoding
3		* Copyright (c) 2005 Fabrice Bellard
4		*
5		* This file is part of FFmpeg.
6		*
7		* FFmpeg is free software; you can redistribute it and/or
8		* modify it under the terms of the GNU Lesser General Public
9		* License as published by the Free Software Foundation; either
10		* version 2.1 of the License, or (at your option) any later version.
11		*
12		* FFmpeg is distributed in the hope that it will be useful,
13		* but WITHOUT ANY WARRANTY; without even the implied warranty of
14		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15		* Lesser General Public License for more details.
16		*
17		* You should have received a copy of the GNU Lesser General Public
18		* License along with FFmpeg; if not, write to the Free Software
19		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20		*/
21		#include "avcodec.h"
22		#include "bytestream.h"
23		#include "codec_internal.h"
24		#include "libavutil/colorspace.h"
25		#include "libavutil/opt.h"
26
27		typedef struct DVBSubtitleContext {
28		AVClass * class;
29		int object_version;
30		int min_bpp;
31		} DVBSubtitleContext;
32
33	0	#define PUTBITS2(val)\
34	0	{\
35	0	bitbuf \|= (val) << bitcnt;\
36	0	bitcnt -= 2;\
37	0	if (bitcnt < 0) {\
38	0	bitcnt = 6;\
39	0	*q++ = bitbuf;\
40	0	bitbuf = 0;\
41	0	}\
42	0	}
43
44		static int dvb_encode_rle2(uint8_t **pq, int buf_size,
45		const uint8_t *bitmap, int linesize,
46		int w, int h)
47	0	{
48	0	uint8_t q, line_begin;
49	0	unsigned int bitbuf;
50	0	int bitcnt;
51	0	int x, y, len, x1, v, color;
52
53	0	q = *pq;
54
55	0	for(y = 0; y < h; y++) {
56		// Worst case line is 3 bits per value + 4 bytes overhead
57	0	if (buf_size * 8 < w * 3 + 32)
58	0	return AVERROR_BUFFER_TOO_SMALL;
59	0	line_begin = q;
60	0	*q++ = 0x10;
61	0	bitbuf = 0;
62	0	bitcnt = 6;
63
64	0	x = 0;
65	0	while (x < w) {
66	0	x1 = x;
67	0	color = bitmap[x1++];
68	0	while (x1 < w && bitmap[x1] == color)
69	0	x1++;
70	0	len = x1 - x;
71	0	if (color == 0 && len == 2) {
72	0	PUTBITS2(0);
73	0	PUTBITS2(0);
74	0	PUTBITS2(1);
75	0	} else if (len >= 3 && len <= 10) {
76	0	v = len - 3;
77	0	PUTBITS2(0);
78	0	PUTBITS2((v >> 2) \| 2);
79	0	PUTBITS2(v & 3);
80	0	PUTBITS2(color);
81	0	} else if (len >= 12 && len <= 27) {
82	0	v = len - 12;
83	0	PUTBITS2(0);
84	0	PUTBITS2(0);
85	0	PUTBITS2(2);
86	0	PUTBITS2(v >> 2);
87	0	PUTBITS2(v & 3);
88	0	PUTBITS2(color);
89	0	} else if (len >= 29) {
90		/* length = 29 ... 284 */
91	0	if (len > 284)
92	0	len = 284;
93	0	v = len - 29;
94	0	PUTBITS2(0);
95	0	PUTBITS2(0);
96	0	PUTBITS2(3);
97	0	PUTBITS2((v >> 6));
98	0	PUTBITS2((v >> 4) & 3);
99	0	PUTBITS2((v >> 2) & 3);
100	0	PUTBITS2(v & 3);
101	0	PUTBITS2(color);
102	0	} else {
103	0	PUTBITS2(color);
104	0	if (color == 0) {
105	0	PUTBITS2(1);
106	0	}
107	0	len = 1;
108	0	}
109	0	x += len;
110	0	}
111		/* end of line */
112	0	PUTBITS2(0);
113	0	PUTBITS2(0);
114	0	PUTBITS2(0);
115	0	if (bitcnt != 6) {
116	0	*q++ = bitbuf;
117	0	}
118	0	*q++ = 0xf0;
119	0	bitmap += linesize;
120	0	buf_size -= q - line_begin;
121	0	}
122	0	len = q - *pq;
123	0	*pq = q;
124	0	return len;
125	0	}
126
127	0	#define PUTBITS4(val)\
128	0	{\
129	0	bitbuf \|= (val) << bitcnt;\
130	0	bitcnt -= 4;\
131	0	if (bitcnt < 0) {\
132	0	bitcnt = 4;\
133	0	*q++ = bitbuf;\
134	0	bitbuf = 0;\
135	0	}\
136	0	}
137
138		/* some DVB decoders only implement 4 bits/pixel */
139		static int dvb_encode_rle4(uint8_t **pq, int buf_size,
140		const uint8_t *bitmap, int linesize,
141		int w, int h)
142	0	{
143	0	uint8_t q, line_begin;
144	0	unsigned int bitbuf;
145	0	int bitcnt;
146	0	int x, y, len, x1, v, color;
147
148	0	q = *pq;
149
150	0	for(y = 0; y < h; y++) {
151		// Worst case line is 6 bits per value, + 4 bytes overhead
152	0	if (buf_size * 8 < w * 6 + 32)
153	0	return AVERROR_BUFFER_TOO_SMALL;
154	0	line_begin = q;
155	0	*q++ = 0x11;
156	0	bitbuf = 0;
157	0	bitcnt = 4;
158
159	0	x = 0;
160	0	while (x < w) {
161	0	x1 = x;
162	0	color = bitmap[x1++];
163	0	while (x1 < w && bitmap[x1] == color)
164	0	x1++;
165	0	len = x1 - x;
166	0	if (color == 0 && len == 2) {
167	0	PUTBITS4(0);
168	0	PUTBITS4(0xd);
169	0	} else if (color == 0 && (len >= 3 && len <= 9)) {
170	0	PUTBITS4(0);
171	0	PUTBITS4(len - 2);
172	0	} else if (len >= 4 && len <= 7) {
173	0	PUTBITS4(0);
174	0	PUTBITS4(8 + len - 4);
175	0	PUTBITS4(color);
176	0	} else if (len >= 9 && len <= 24) {
177	0	PUTBITS4(0);
178	0	PUTBITS4(0xe);
179	0	PUTBITS4(len - 9);
180	0	PUTBITS4(color);
181	0	} else if (len >= 25) {
182	0	if (len > 280)
183	0	len = 280;
184	0	v = len - 25;
185	0	PUTBITS4(0);
186	0	PUTBITS4(0xf);
187	0	PUTBITS4(v >> 4);
188	0	PUTBITS4(v & 0xf);
189	0	PUTBITS4(color);
190	0	} else {
191	0	PUTBITS4(color);
192	0	if (color == 0) {
193	0	PUTBITS4(0xc);
194	0	}
195	0	len = 1;
196	0	}
197	0	x += len;
198	0	}
199		/* end of line */
200	0	PUTBITS4(0);
201	0	PUTBITS4(0);
202	0	if (bitcnt != 4) {
203	0	*q++ = bitbuf;
204	0	}
205	0	*q++ = 0xf0;
206	0	bitmap += linesize;
207	0	buf_size -= q - line_begin;
208	0	}
209	0	len = q - *pq;
210	0	*pq = q;
211	0	return len;
212	0	}
213
214		static int dvb_encode_rle8(uint8_t **pq, int buf_size,
215		const uint8_t *bitmap, int linesize,
216		int w, int h)
217	0	{
218	0	uint8_t q, line_begin;
219	0	int x, y, len, x1, color;
220
221	0	q = *pq;
222
223	0	for (y = 0; y < h; y++) {
224		// Worst case line is 12 bits per value, + 3 bytes overhead
225	0	if (buf_size * 8 < w * 12 + 24)
226	0	return AVERROR_BUFFER_TOO_SMALL;
227	0	line_begin = q;
228	0	*q++ = 0x12;
229
230	0	x = 0;
231	0	while (x < w) {
232	0	x1 = x;
233	0	color = bitmap[x1++];
234	0	while (x1 < w && bitmap[x1] == color)
235	0	x1++;
236	0	len = x1 - x;
237	0	if (len == 1 && color) {
238		// 00000001 to 11111111 1 pixel in colour x
239	0	*q++ = color;
240	0	} else {
241	0	if (color == 0x00) {
242		// 00000000 0LLLLLLL L pixels (1-127) in colour 0 (L > 0)
243	0	len = FFMIN(len, 127);
244	0	*q++ = 0x00;
245	0	*q++ = len;
246	0	} else if (len > 2) {
247		// 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2)
248	0	len = FFMIN(len, 127);
249	0	*q++ = 0x00;
250	0	*q++ = 0x80+len;
251	0	*q++ = color;
252	0	}
253	0	else if (len == 2) {
254	0	*q++ = color;
255	0	*q++ = color;
256	0	} else {
257	0	*q++ = color;
258	0	len = 1;
259	0	}
260	0	}
261	0	x += len;
262	0	}
263		/* end of line */
264		// 00000000 00000000 end of 8-bit/pixel_code_string
265	0	*q++ = 0x00;
266	0	*q++ = 0x00;
267	0	*q++ = 0xf0;
268	0	bitmap += linesize;
269	0	buf_size -= q - line_begin;
270	0	}
271	0	len = q - *pq;
272	0	*pq = q;
273	0	return len;
274	0	}
275
276		static int dvbsub_encode(AVCodecContext avctx, uint8_t outbuf, int buf_size,
277		const AVSubtitle *h)
278	0	{
279	0	DVBSubtitleContext *s = avctx->priv_data;
280	0	uint8_t q, pseg_len;
281	0	int page_id, region_id, clut_id, object_id, i, bpp_index, page_state, min_colors;
282
283
284	0	q = outbuf;
285
286	0	page_id = 1;
287
288	0	switch(s->min_bpp) {
289	0	case 2:
290	0	case 4:
291	0	case 8:
292	0	min_colors = 1 << s->min_bpp;
293	0	break;
294	0	default:
295	0	av_log(avctx, AV_LOG_ERROR, "Invalid min_bpp value %d.\n", s->min_bpp);
296	0	return AVERROR(EINVAL);
297	0	}
298
299	0	if (h->num_rects && !h->rects)
300	0	return AVERROR(EINVAL);
301
302	0	if (h->num_rects >= 256)
303	0	return AVERROR(EINVAL);
304
305	0	if (avctx->width > 0 && avctx->height > 0) {
306	0	if (buf_size < 11)
307	0	return AVERROR_BUFFER_TOO_SMALL;
308		/* display definition segment */
309	0	q++ = 0x0f; / sync_byte */
310	0	q++ = 0x14; / segment_type */
311	0	bytestream_put_be16(&q, page_id);
312	0	pseg_len = q;
313	0	q += 2; /* segment length */
314	0	q++ = 0x00; / dds version number & display window flag */
315	0	bytestream_put_be16(&q, avctx->width - 1); /* display width */
316	0	bytestream_put_be16(&q, avctx->height - 1); /* display height */
317	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
318	0	buf_size -= 11;
319	0	}
320
321		/* page composition segment */
322
323	0	if (buf_size < 8 + h->num_rects * 6)
324	0	return AVERROR_BUFFER_TOO_SMALL;
325	0	q++ = 0x0f; / sync_byte */
326	0	q++ = 0x10; / segment_type */
327	0	bytestream_put_be16(&q, page_id);
328	0	pseg_len = q;
329	0	q += 2; /* segment length */
330	0	q++ = 30; / page_timeout (seconds) */
331	0	page_state = 2; /* mode change */
332		/* page_version = 0 + page_state */
333	0	*q++ = (s->object_version << 4) \| (page_state << 2) \| 3;
334
335	0	for (region_id = 0; region_id < h->num_rects; region_id++) {
336	0	*q++ = region_id;
337	0	q++ = 0xff; / reserved */
338	0	bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */
339	0	bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */
340	0	}
341
342	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
343	0	buf_size -= 8 + h->num_rects * 6;
344
345	0	if (h->num_rects) {
346	0	for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
347		/* CLUT segment */
348	0	int nb_colors = FFMAX(min_colors, h->rects[clut_id]->nb_colors);
349
350	0	if (nb_colors <= 4U) {
351		/* 2 bpp, some decoders do not support it correctly */
352	0	bpp_index = 0;
353	0	} else if (nb_colors <= 16U) {
354		/* 4 bpp, standard encoding */
355	0	bpp_index = 1;
356	0	} else if (nb_colors <= 256U) {
357		/* 8 bpp, standard encoding */
358	0	bpp_index = 2;
359	0	} else {
360	0	return AVERROR(EINVAL);
361	0	}
362
363	0	if (buf_size < 6 + h->rects[clut_id]->nb_colors * 6)
364	0	return AVERROR_BUFFER_TOO_SMALL;
365
366		/* CLUT segment */
367	0	q++ = 0x0f; / sync byte */
368	0	q++ = 0x12; / CLUT definition segment */
369	0	bytestream_put_be16(&q, page_id);
370	0	pseg_len = q;
371	0	q += 2; /* segment length */
372	0	*q++ = clut_id;
373	0	q++ = (0 << 4) \| 0xf; / version = 0 */
374
375	0	for(i = 0; i < h->rects[clut_id]->nb_colors; i++) {
376	0	q++ = i; / clut_entry_id */
377	0	q++ = (1 << (7 - bpp_index)) \| (0xf << 1) \| 1; / 2 bits/pixel full range */
378	0	{
379	0	int a, r, g, b;
380	0	uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i];
381	0	a = (x >> 24) & 0xff;
382	0	r = (x >> 16) & 0xff;
383	0	g = (x >> 8) & 0xff;
384	0	b = (x >> 0) & 0xff;
385
386	0	*q++ = RGB_TO_Y_CCIR(r, g, b);
387	0	*q++ = RGB_TO_V_CCIR(r, g, b, 0);
388	0	*q++ = RGB_TO_U_CCIR(r, g, b, 0);
389	0	*q++ = 255 - a;
390	0	}
391	0	}
392
393	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
394	0	buf_size -= 6 + h->rects[clut_id]->nb_colors * 6;
395	0	}
396
397	0	if (buf_size < h->num_rects * 22)
398	0	return AVERROR_BUFFER_TOO_SMALL;
399	0	for (region_id = 0; region_id < h->num_rects; region_id++) {
400
401		/* region composition segment */
402	0	int nb_colors = FFMAX(min_colors, h->rects[region_id]->nb_colors);
403
404	0	if (nb_colors <= 4) {
405		/* 2 bpp, some decoders do not support it correctly */
406	0	bpp_index = 0;
407	0	} else if (nb_colors <= 16) {
408		/* 4 bpp, standard encoding */
409	0	bpp_index = 1;
410	0	} else if (nb_colors <= 256) {
411		/* 8 bpp, standard encoding */
412	0	bpp_index = 2;
413	0	} else {
414	0	return AVERROR(EINVAL);
415	0	}
416
417	0	q++ = 0x0f; / sync_byte */
418	0	q++ = 0x11; / segment_type */
419	0	bytestream_put_be16(&q, page_id);
420	0	pseg_len = q;
421	0	q += 2; /* segment length */
422	0	*q++ = region_id;
423	0	q++ = (s->object_version << 4) \| (0 << 3) \| 0x07; / version , no fill */
424	0	bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */
425	0	bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */
426	0	*q++ = ((1 + bpp_index) << 5) \| ((1 + bpp_index) << 2) \| 0x03;
427	0	q++ = region_id; / clut_id == region_id */
428	0	q++ = 0; / 8 bit fill colors */
429	0	q++ = 0x03; / 4 bit and 2 bit fill colors */
430
431	0	bytestream_put_be16(&q, region_id); /* object_id == region_id */
432	0	*q++ = (0 << 6) \| (0 << 4);
433	0	*q++ = 0;
434	0	*q++ = 0xf0;
435	0	*q++ = 0;
436
437	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
438	0	}
439	0	buf_size -= h->num_rects * 22;
440
441	0	for (object_id = 0; object_id < h->num_rects; object_id++) {
442	0	int (dvb_encode_rle)(uint8_t *pq, int buf_size,
443	0	const uint8_t *bitmap, int linesize,
444	0	int w, int h);
445
446	0	int nb_colors = FFMAX(min_colors, h->rects[object_id]->nb_colors);
447
448	0	if (buf_size < 13)
449	0	return AVERROR_BUFFER_TOO_SMALL;
450
451		/* bpp_index maths */
452	0	if (nb_colors <= 4) {
453		/* 2 bpp, some decoders do not support it correctly */
454	0	dvb_encode_rle = dvb_encode_rle2;
455	0	} else if (nb_colors <= 16) {
456		/* 4 bpp, standard encoding */
457	0	dvb_encode_rle = dvb_encode_rle4;
458	0	} else if (nb_colors <= 256) {
459		/* 8 bpp, standard encoding */
460	0	dvb_encode_rle = dvb_encode_rle8;
461	0	} else {
462	0	return AVERROR(EINVAL);
463	0	}
464
465		/* Object Data segment */
466	0	q++ = 0x0f; / sync byte */
467	0	*q++ = 0x13;
468	0	bytestream_put_be16(&q, page_id);
469	0	pseg_len = q;
470	0	q += 2; /* segment length */
471
472	0	bytestream_put_be16(&q, object_id);
473	0	q++ = (s->object_version << 4) \| (0 << 2) \| (0 << 1) \| 1; / version = 0,
474		object_coding_method,
475		non_modifying_color_flag */
476	0	{
477	0	uint8_t ptop_field_len, pbottom_field_len, top_ptr, bottom_ptr;
478	0	int ret;
479
480	0	ptop_field_len = q;
481	0	q += 2;
482	0	pbottom_field_len = q;
483	0	q += 2;
484	0	buf_size -= 13;
485
486	0	top_ptr = q;
487	0	ret = dvb_encode_rle(&q, buf_size,
488	0	h->rects[object_id]->data[0],
489	0	h->rects[object_id]->w * 2,
490	0	h->rects[object_id]->w,
491	0	h->rects[object_id]->h >> 1);
492	0	if (ret < 0)
493	0	return ret;
494	0	buf_size -= ret;
495	0	bottom_ptr = q;
496	0	ret = dvb_encode_rle(&q, buf_size,
497	0	h->rects[object_id]->data[0] + h->rects[object_id]->w,
498	0	h->rects[object_id]->w * 2,
499	0	h->rects[object_id]->w,
500	0	h->rects[object_id]->h >> 1);
501	0	if (ret < 0)
502	0	return ret;
503	0	buf_size -= ret;
504
505	0	bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
506	0	bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
507	0	}
508
509	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
510	0	}
511	0	}
512
513		/* end of display set segment */
514
515	0	if (buf_size < 6)
516	0	return AVERROR_BUFFER_TOO_SMALL;
517	0	q++ = 0x0f; / sync_byte */
518	0	q++ = 0x80; / segment_type */
519	0	bytestream_put_be16(&q, page_id);
520	0	pseg_len = q;
521	0	q += 2; /* segment length */
522
523	0	bytestream_put_be16(&pseg_len, q - pseg_len - 2);
524	0	buf_size -= 6;
525
526	0	s->object_version = (s->object_version + 1) & 0xf;
527	0	return q - outbuf;
528	0	}
529
530		#define OFFSET(x) offsetof(DVBSubtitleContext, x)
531		#define SE AV_OPT_FLAG_SUBTITLE_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
532		static const AVOption options[] = {
533		{"min_bpp", "minimum bits-per-pixel for subtitle colors (2, 4 or 8)", OFFSET(min_bpp), AV_OPT_TYPE_INT, {.i64 = 4}, 2, 8, SE},
534		{ NULL },
535		};
536
537		static const AVClass dvbsubenc_class = {
538		.class_name = "DVBSUB subtitle encoder",
539		.item_name = av_default_item_name,
540		.option = options,
541		.version = LIBAVUTIL_VERSION_INT,
542		};
543
544		const FFCodec ff_dvbsub_encoder = {
545		.p.name = "dvbsub",
546		CODEC_LONG_NAME("DVB subtitles"),
547		.p.type = AVMEDIA_TYPE_SUBTITLE,
548		.p.id = AV_CODEC_ID_DVB_SUBTITLE,
549		.priv_data_size = sizeof(DVBSubtitleContext),
550		FF_CODEC_ENCODE_SUB_CB(dvbsub_encode),
551		.p.priv_class = &dvbsubenc_class,
552		};