| /* |
| * DVD subtitle encoding |
| * Copyright (c) 2005 Wolfram Gloger |
| * |
| * 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 "internal.h" |
| #include "libavutil/avassert.h" |
| #include "libavutil/bprint.h" |
| #include "libavutil/imgutils.h" |
| #include "libavutil/opt.h" |
| |
| typedef struct { |
| AVClass *class; |
| uint32_t global_palette[16]; |
| int even_rows_fix; |
| } DVDSubtitleContext; |
| |
| // ncnt is the nibble counter |
| #define PUTNIBBLE(val)\ |
| do {\ |
| if (ncnt++ & 1)\ |
| *q++ = bitbuf | ((val) & 0x0f);\ |
| else\ |
| bitbuf = (val) << 4;\ |
| } while(0) |
| |
| static void dvd_encode_rle(uint8_t **pq, |
| const uint8_t *bitmap, int linesize, |
| int w, int h, |
| const int cmap[256]) |
| { |
| uint8_t *q; |
| unsigned int bitbuf = 0; |
| int ncnt; |
| int x, y, len, color; |
| |
| q = *pq; |
| |
| for (y = 0; y < h; ++y) { |
| ncnt = 0; |
| for(x = 0; x < w; x += len) { |
| color = bitmap[x]; |
| for (len=1; x+len < w; ++len) |
| if (bitmap[x+len] != color) |
| break; |
| color = cmap[color]; |
| av_assert0(color < 4); |
| if (len < 0x04) { |
| PUTNIBBLE((len << 2)|color); |
| } else if (len < 0x10) { |
| PUTNIBBLE(len >> 2); |
| PUTNIBBLE((len << 2)|color); |
| } else if (len < 0x40) { |
| PUTNIBBLE(0); |
| PUTNIBBLE(len >> 2); |
| PUTNIBBLE((len << 2)|color); |
| } else if (x+len == w) { |
| PUTNIBBLE(0); |
| PUTNIBBLE(0); |
| PUTNIBBLE(0); |
| PUTNIBBLE(color); |
| } else { |
| if (len > 0xff) |
| len = 0xff; |
| PUTNIBBLE(0); |
| PUTNIBBLE(len >> 6); |
| PUTNIBBLE(len >> 2); |
| PUTNIBBLE((len << 2)|color); |
| } |
| } |
| /* end of line */ |
| if (ncnt & 1) |
| PUTNIBBLE(0); |
| bitmap += linesize; |
| } |
| |
| *pq = q; |
| } |
| |
| static int color_distance(uint32_t a, uint32_t b) |
| { |
| int r = 0, d, i; |
| int alpha_a = 8, alpha_b = 8; |
| |
| for (i = 24; i >= 0; i -= 8) { |
| d = alpha_a * (int)((a >> i) & 0xFF) - |
| alpha_b * (int)((b >> i) & 0xFF); |
| r += d * d; |
| alpha_a = a >> 28; |
| alpha_b = b >> 28; |
| } |
| return r; |
| } |
| |
| /** |
| * Count colors used in a rectangle, quantizing alpha and grouping by |
| * nearest global palette entry. |
| */ |
| static void count_colors(AVCodecContext *avctx, unsigned hits[33], |
| const AVSubtitleRect *r) |
| { |
| DVDSubtitleContext *dvdc = avctx->priv_data; |
| unsigned count[256] = { 0 }; |
| uint32_t *palette = (uint32_t *)r->data[1]; |
| uint32_t color; |
| int x, y, i, j, match, d, best_d, av_uninit(best_j); |
| uint8_t *p = r->data[0]; |
| |
| for (y = 0; y < r->h; y++) { |
| for (x = 0; x < r->w; x++) |
| count[*(p++)]++; |
| p += r->linesize[0] - r->w; |
| } |
| for (i = 0; i < 256; i++) { |
| if (!count[i]) /* avoid useless search */ |
| continue; |
| color = palette[i]; |
| /* 0: transparent, 1-16: semi-transparent, 17-33 opaque */ |
| match = color < 0x33000000 ? 0 : color < 0xCC000000 ? 1 : 17; |
| if (match) { |
| best_d = INT_MAX; |
| for (j = 0; j < 16; j++) { |
| d = color_distance(0xFF000000 | color, |
| 0xFF000000 | dvdc->global_palette[j]); |
| if (d < best_d) { |
| best_d = d; |
| best_j = j; |
| } |
| } |
| match += best_j; |
| } |
| hits[match] += count[i]; |
| } |
| } |
| |
| static void select_palette(AVCodecContext *avctx, int out_palette[4], |
| int out_alpha[4], unsigned hits[33]) |
| { |
| DVDSubtitleContext *dvdc = avctx->priv_data; |
| int i, j, bright, mult; |
| uint32_t color; |
| int selected[4] = { 0 }; |
| uint32_t pseudopal[33] = { 0 }; |
| uint32_t refcolor[3] = { 0x00000000, 0xFFFFFFFF, 0xFF000000 }; |
| |
| /* Bonus for transparent: if the rectangle fits tightly the text, the |
| background color can be quite rare, but it would be ugly without it */ |
| hits[0] *= 16; |
| /* Bonus for bright colors */ |
| for (i = 0; i < 16; i++) { |
| if (!(hits[1 + i] + hits[17 + i])) |
| continue; /* skip unused colors to gain time */ |
| color = dvdc->global_palette[i]; |
| bright = 0; |
| for (j = 0; j < 3; j++, color >>= 8) |
| bright += (color & 0xFF) < 0x40 || (color & 0xFF) >= 0xC0; |
| mult = 2 + FFMIN(bright, 2); |
| hits[ 1 + i] *= mult; |
| hits[17 + i] *= mult; |
| } |
| |
| /* Select four most frequent colors */ |
| for (i = 0; i < 4; i++) { |
| for (j = 0; j < 33; j++) |
| if (hits[j] > hits[selected[i]]) |
| selected[i] = j; |
| hits[selected[i]] = 0; |
| } |
| |
| /* Order the colors like in most DVDs: |
| 0: background, 1: foreground, 2: outline */ |
| for (i = 0; i < 16; i++) { |
| pseudopal[ 1 + i] = 0x80000000 | dvdc->global_palette[i]; |
| pseudopal[17 + i] = 0xFF000000 | dvdc->global_palette[i]; |
| } |
| for (i = 0; i < 3; i++) { |
| int best_d = color_distance(refcolor[i], pseudopal[selected[i]]); |
| for (j = i + 1; j < 4; j++) { |
| int d = color_distance(refcolor[i], pseudopal[selected[j]]); |
| if (d < best_d) { |
| FFSWAP(int, selected[i], selected[j]); |
| best_d = d; |
| } |
| } |
| } |
| |
| /* Output */ |
| for (i = 0; i < 4; i++) { |
| out_palette[i] = selected[i] ? (selected[i] - 1) & 0xF : 0; |
| out_alpha [i] = !selected[i] ? 0 : selected[i] < 17 ? 0x80 : 0xFF; |
| } |
| } |
| |
| static void build_color_map(AVCodecContext *avctx, int cmap[], |
| const uint32_t palette[], |
| const int out_palette[], unsigned int const out_alpha[]) |
| { |
| DVDSubtitleContext *dvdc = avctx->priv_data; |
| int i, j, d, best_d; |
| uint32_t pseudopal[4]; |
| |
| for (i = 0; i < 4; i++) |
| pseudopal[i] = (out_alpha[i] << 24) | |
| dvdc->global_palette[out_palette[i]]; |
| for (i = 0; i < 256; i++) { |
| best_d = INT_MAX; |
| for (j = 0; j < 4; j++) { |
| d = color_distance(pseudopal[j], palette[i]); |
| if (d < best_d) { |
| cmap[i] = j; |
| best_d = d; |
| } |
| } |
| } |
| } |
| |
| static void copy_rectangle(AVSubtitleRect *dst, AVSubtitleRect *src, int cmap[]) |
| { |
| int x, y; |
| uint8_t *p, *q; |
| |
| p = src->data[0]; |
| q = dst->data[0] + (src->x - dst->x) + |
| (src->y - dst->y) * dst->linesize[0]; |
| for (y = 0; y < src->h; y++) { |
| for (x = 0; x < src->w; x++) |
| *(q++) = cmap[*(p++)]; |
| p += src->linesize[0] - src->w; |
| q += dst->linesize[0] - src->w; |
| } |
| } |
| |
| static int encode_dvd_subtitles(AVCodecContext *avctx, |
| uint8_t *outbuf, int outbuf_size, |
| const AVSubtitle *h) |
| { |
| DVDSubtitleContext *dvdc = avctx->priv_data; |
| uint8_t *q, *qq; |
| int offset1, offset2; |
| int i, rects = h->num_rects, ret; |
| unsigned global_palette_hits[33] = { 0 }; |
| int cmap[256]; |
| int out_palette[4]; |
| int out_alpha[4]; |
| AVSubtitleRect vrect; |
| uint8_t *vrect_data = NULL; |
| int x2, y2; |
| int forced = 0; |
| |
| if (rects == 0 || !h->rects) |
| return AVERROR(EINVAL); |
| for (i = 0; i < rects; i++) |
| if (h->rects[i]->type != SUBTITLE_BITMAP) { |
| av_log(avctx, AV_LOG_ERROR, "Bitmap subtitle required\n"); |
| return AVERROR(EINVAL); |
| } |
| /* Mark this subtitle forced if any of the rectangles is forced. */ |
| for (i = 0; i < rects; i++) |
| if ((h->rects[i]->flags & AV_SUBTITLE_FLAG_FORCED) != 0) { |
| forced = 1; |
| break; |
| } |
| |
| #if FF_API_AVPICTURE |
| FF_DISABLE_DEPRECATION_WARNINGS |
| for (i = 0; i < rects; i++) |
| if (!h->rects[i]->data[0]) { |
| AVSubtitleRect *rect = h->rects[i]; |
| int j; |
| for (j = 0; j < 4; j++) { |
| rect->data[j] = rect->pict.data[j]; |
| rect->linesize[j] = rect->pict.linesize[j]; |
| } |
| } |
| FF_ENABLE_DEPRECATION_WARNINGS |
| #endif |
| |
| vrect = *h->rects[0]; |
| |
| if (rects > 1) { |
| /* DVD subtitles can have only one rectangle: build a virtual |
| rectangle containing all actual rectangles. |
| The data of the rectangles will be copied later, when the palette |
| is decided, because the rectangles may have different palettes. */ |
| int xmin = h->rects[0]->x, xmax = xmin + h->rects[0]->w; |
| int ymin = h->rects[0]->y, ymax = ymin + h->rects[0]->h; |
| for (i = 1; i < rects; i++) { |
| xmin = FFMIN(xmin, h->rects[i]->x); |
| ymin = FFMIN(ymin, h->rects[i]->y); |
| xmax = FFMAX(xmax, h->rects[i]->x + h->rects[i]->w); |
| ymax = FFMAX(ymax, h->rects[i]->y + h->rects[i]->h); |
| } |
| vrect.x = xmin; |
| vrect.y = ymin; |
| vrect.w = xmax - xmin; |
| vrect.h = ymax - ymin; |
| if ((ret = av_image_check_size(vrect.w, vrect.h, 0, avctx)) < 0) |
| return ret; |
| |
| /* Count pixels outside the virtual rectangle as transparent */ |
| global_palette_hits[0] = vrect.w * vrect.h; |
| for (i = 0; i < rects; i++) |
| global_palette_hits[0] -= h->rects[i]->w * h->rects[i]->h; |
| } |
| |
| for (i = 0; i < rects; i++) |
| count_colors(avctx, global_palette_hits, h->rects[i]); |
| select_palette(avctx, out_palette, out_alpha, global_palette_hits); |
| |
| if (rects > 1) { |
| if (!(vrect_data = av_calloc(vrect.w, vrect.h))) |
| return AVERROR(ENOMEM); |
| vrect.data [0] = vrect_data; |
| vrect.linesize[0] = vrect.w; |
| for (i = 0; i < rects; i++) { |
| build_color_map(avctx, cmap, (uint32_t *)h->rects[i]->data[1], |
| out_palette, out_alpha); |
| copy_rectangle(&vrect, h->rects[i], cmap); |
| } |
| for (i = 0; i < 4; i++) |
| cmap[i] = i; |
| } else { |
| build_color_map(avctx, cmap, (uint32_t *)h->rects[0]->data[1], |
| out_palette, out_alpha); |
| } |
| |
| av_log(avctx, AV_LOG_DEBUG, "Selected palette:"); |
| for (i = 0; i < 4; i++) |
| av_log(avctx, AV_LOG_DEBUG, " 0x%06x@@%02x (0x%x,0x%x)", |
| dvdc->global_palette[out_palette[i]], out_alpha[i], |
| out_palette[i], out_alpha[i] >> 4); |
| av_log(avctx, AV_LOG_DEBUG, "\n"); |
| |
| // encode data block |
| q = outbuf + 4; |
| offset1 = q - outbuf; |
| // worst case memory requirement: 1 nibble per pixel.. |
| if ((q - outbuf) + vrect.w * vrect.h / 2 + 17 + 21 > outbuf_size) { |
| av_log(NULL, AV_LOG_ERROR, "dvd_subtitle too big\n"); |
| ret = AVERROR_BUFFER_TOO_SMALL; |
| goto fail; |
| } |
| dvd_encode_rle(&q, vrect.data[0], vrect.w * 2, |
| vrect.w, (vrect.h + 1) >> 1, cmap); |
| offset2 = q - outbuf; |
| dvd_encode_rle(&q, vrect.data[0] + vrect.w, vrect.w * 2, |
| vrect.w, vrect.h >> 1, cmap); |
| |
| if (dvdc->even_rows_fix && (vrect.h & 1)) { |
| // Work-around for some players that want the height to be even. |
| vrect.h++; |
| *q++ = 0x00; // 0x00 0x00 == empty row, i.e. fully transparent |
| *q++ = 0x00; |
| } |
| |
| // set data packet size |
| qq = outbuf + 2; |
| bytestream_put_be16(&qq, q - outbuf); |
| |
| // send start display command |
| bytestream_put_be16(&q, (h->start_display_time*90) >> 10); |
| bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12 + 2); |
| *q++ = 0x03; // palette - 4 nibbles |
| *q++ = (out_palette[3] << 4) | out_palette[2]; |
| *q++ = (out_palette[1] << 4) | out_palette[0]; |
| *q++ = 0x04; // alpha - 4 nibbles |
| *q++ = (out_alpha[3] & 0xF0) | (out_alpha[2] >> 4); |
| *q++ = (out_alpha[1] & 0xF0) | (out_alpha[0] >> 4); |
| |
| // 12 bytes per rect |
| x2 = vrect.x + vrect.w - 1; |
| y2 = vrect.y + vrect.h - 1; |
| |
| *q++ = 0x05; |
| // x1 x2 -> 6 nibbles |
| *q++ = vrect.x >> 4; |
| *q++ = (vrect.x << 4) | ((x2 >> 8) & 0xf); |
| *q++ = x2; |
| // y1 y2 -> 6 nibbles |
| *q++ = vrect.y >> 4; |
| *q++ = (vrect.y << 4) | ((y2 >> 8) & 0xf); |
| *q++ = y2; |
| |
| *q++ = 0x06; |
| // offset1, offset2 |
| bytestream_put_be16(&q, offset1); |
| bytestream_put_be16(&q, offset2); |
| |
| *q++ = forced ? 0x00 : 0x01; // start command |
| *q++ = 0xff; // terminating command |
| |
| // send stop display command last |
| bytestream_put_be16(&q, (h->end_display_time*90) >> 10); |
| bytestream_put_be16(&q, (q - outbuf) - 2 /*+ 4*/); |
| *q++ = 0x02; // set end |
| *q++ = 0xff; // terminating command |
| |
| qq = outbuf; |
| bytestream_put_be16(&qq, q - outbuf); |
| |
| av_log(NULL, AV_LOG_DEBUG, "subtitle_packet size=%"PTRDIFF_SPECIFIER"\n", q - outbuf); |
| ret = q - outbuf; |
| |
| fail: |
| av_free(vrect_data); |
| return ret; |
| } |
| |
| static int dvdsub_init(AVCodecContext *avctx) |
| { |
| DVDSubtitleContext *dvdc = avctx->priv_data; |
| static const uint32_t default_palette[16] = { |
| 0x000000, 0x0000FF, 0x00FF00, 0xFF0000, |
| 0xFFFF00, 0xFF00FF, 0x00FFFF, 0xFFFFFF, |
| 0x808000, 0x8080FF, 0x800080, 0x80FF80, |
| 0x008080, 0xFF8080, 0x555555, 0xAAAAAA, |
| }; |
| AVBPrint extradata; |
| int i, ret; |
| |
| av_assert0(sizeof(dvdc->global_palette) == sizeof(default_palette)); |
| memcpy(dvdc->global_palette, default_palette, sizeof(dvdc->global_palette)); |
| |
| av_bprint_init(&extradata, 0, 1); |
| if (avctx->width && avctx->height) |
| av_bprintf(&extradata, "size: %dx%d\n", avctx->width, avctx->height); |
| av_bprintf(&extradata, "palette:"); |
| for (i = 0; i < 16; i++) |
| av_bprintf(&extradata, " %06"PRIx32"%c", |
| dvdc->global_palette[i] & 0xFFFFFF, i < 15 ? ',' : '\n'); |
| |
| ret = avpriv_bprint_to_extradata(avctx, &extradata); |
| if (ret < 0) |
| return ret; |
| |
| return 0; |
| } |
| |
| static int dvdsub_encode(AVCodecContext *avctx, |
| unsigned char *buf, int buf_size, |
| const AVSubtitle *sub) |
| { |
| //DVDSubtitleContext *s = avctx->priv_data; |
| int ret; |
| |
| ret = encode_dvd_subtitles(avctx, buf, buf_size, sub); |
| return ret; |
| } |
| |
| #define OFFSET(x) offsetof(DVDSubtitleContext, x) |
| #define SE AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM |
| static const AVOption options[] = { |
| {"even_rows_fix", "Make number of rows even (workaround for some players)", OFFSET(even_rows_fix), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SE}, |
| { NULL }, |
| }; |
| |
| static const AVClass dvdsubenc_class = { |
| .class_name = "VOBSUB subtitle encoder", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVCodec ff_dvdsub_encoder = { |
| .name = "dvdsub", |
| .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"), |
| .type = AVMEDIA_TYPE_SUBTITLE, |
| .id = AV_CODEC_ID_DVD_SUBTITLE, |
| .init = dvdsub_init, |
| .encode_sub = dvdsub_encode, |
| .priv_class = &dvdsubenc_class, |
| .priv_data_size = sizeof(DVDSubtitleContext), |
| }; |
