diff options
Diffstat (limited to 'libavcodec/dvdsubenc.c')
| -rw-r--r-- | libavcodec/dvdsubenc.c | 387 |
1 files changed, 300 insertions, 87 deletions
diff --git a/libavcodec/dvdsubenc.c b/libavcodec/dvdsubenc.c index c41a983..d913708 100644 --- a/libavcodec/dvdsubenc.c +++ b/libavcodec/dvdsubenc.c @@ -2,27 +2,31 @@ * DVD subtitle encoding * Copyright (c) 2005 Wolfram Gloger * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * 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 "libavutil/avassert.h" +#include "libavutil/bprint.h" +#include "libavutil/imgutils.h" -#undef NDEBUG -#include <assert.h> +typedef struct { + uint32_t global_palette[16]; +} DVDSubtitleContext; // ncnt is the nibble counter #define PUTNIBBLE(val)\ @@ -53,7 +57,7 @@ static void dvd_encode_rle(uint8_t **pq, if (bitmap[x+len] != color) break; color = cmap[color]; - assert(color < 4); + av_assert0(color < 4); if (len < 0x04) { PUTNIBBLE((len << 2)|color); } else if (len < 0x10) { @@ -86,73 +90,247 @@ static void dvd_encode_rle(uint8_t **pq, *pq = q; } -static int encode_dvd_subtitles(uint8_t *outbuf, int outbuf_size, +static int color_distance(uint32_t a, uint32_t b) +{ + int r = 0, d, i; + + for (i = 0; i < 32; i += 8) { + d = ((a >> i) & 0xFF) - ((b >> i) & 0xFF); + r += d * d; + } + 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->pict.data[1]; + uint32_t color; + int x, y, i, j, match, d, best_d, av_uninit(best_j); + uint8_t *p = r->pict.data[0]; + + for (y = 0; y < r->h; y++) { + for (x = 0; x < r->w; x++) + count[*(p++)]++; + p += r->pict.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(color & 0xFFFFFF, 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[], 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->pict.data[0]; + q = dst->pict.data[0] + (src->x - dst->x) + + (src->y - dst->y) * dst->pict.linesize[0]; + for (y = 0; y < src->h; y++) { + for (x = 0; x < src->w; x++) + *(q++) = cmap[*(p++)]; + p += src->pict.linesize[0] - src->w; + q += dst->pict.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 object_id; - int offset1[20], offset2[20]; - int i, imax, color, alpha, rects = h->num_rects; - unsigned long hmax; - unsigned long hist[256]; - int cmap[256]; + 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; if (rects == 0 || h->rects == NULL) - return -1; - if (rects > 20) - rects = 20; - - // analyze bitmaps, compress to 4 colors - for (i=0; i<256; ++i) { - hist[i] = 0; - cmap[i] = 0; + 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); + } + 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 (object_id = 0; object_id < rects; object_id++) - for (i=0; i<h->rects[object_id]->w*h->rects[object_id]->h; ++i) { - color = h->rects[object_id]->pict.data[0][i]; - // only count non-transparent pixels - alpha = ((uint32_t*)h->rects[object_id]->pict.data[1])[color] >> 24; - hist[color] += alpha; + + 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.pict.data [0] = vrect_data; + vrect.pict.linesize[0] = vrect.w; + for (i = 0; i < rects; i++) { + build_color_map(avctx, cmap, (uint32_t *)h->rects[i]->pict.data[1], + out_palette, out_alpha); + copy_rectangle(&vrect, h->rects[i], cmap); } - for (color=3;; --color) { - hmax = 0; - imax = 0; - for (i=0; i<256; ++i) - if (hist[i] > hmax) { - imax = i; - hmax = hist[i]; - } - if (hmax == 0) - break; - if (color == 0) - color = 3; - av_log(NULL, AV_LOG_DEBUG, "dvd_subtitle hist[%d]=%ld -> col %d\n", - imax, hist[imax], color); - cmap[imax] = color; - hist[imax] = 0; + for (i = 0; i < 4; i++) + cmap[i] = i; + } else { + build_color_map(avctx, cmap, (uint32_t *)h->rects[0]->pict.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; - for (object_id = 0; object_id < rects; object_id++) { - offset1[object_id] = q - outbuf; - // worst case memory requirement: 1 nibble per pixel.. - if ((q - outbuf) + h->rects[object_id]->w*h->rects[object_id]->h/2 - + 17*rects + 21 > outbuf_size) { - av_log(NULL, AV_LOG_ERROR, "dvd_subtitle too big\n"); - return -1; - } - dvd_encode_rle(&q, h->rects[object_id]->pict.data[0], - h->rects[object_id]->w*2, - h->rects[object_id]->w, h->rects[object_id]->h >> 1, - cmap); - offset2[object_id] = q - outbuf; - dvd_encode_rle(&q, h->rects[object_id]->pict.data[0] + h->rects[object_id]->w, - h->rects[object_id]->w*2, - h->rects[object_id]->w, h->rects[object_id]->h >> 1, - cmap); + 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.pict.data[0], vrect.w * 2, + vrect.w, (vrect.h + 1) >> 1, cmap); + offset2 = q - outbuf; + dvd_encode_rle(&q, vrect.pict.data[0] + vrect.w, vrect.w * 2, + vrect.w, vrect.h >> 1, cmap); // set data packet size qq = outbuf + 2; @@ -160,34 +338,33 @@ static int encode_dvd_subtitles(uint8_t *outbuf, int outbuf_size, // send start display command bytestream_put_be16(&q, (h->start_display_time*90) >> 10); - bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12*rects + 2); + bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12 + 2); *q++ = 0x03; // palette - 4 nibbles - *q++ = 0x03; *q++ = 0x7f; + *q++ = (out_palette[3] << 4) | out_palette[2]; + *q++ = (out_palette[1] << 4) | out_palette[0]; *q++ = 0x04; // alpha - 4 nibbles - *q++ = 0xf0; *q++ = 0x00; - //*q++ = 0x0f; *q++ = 0xff; + *q++ = (out_alpha[3] & 0xF0) | (out_alpha[2] >> 4); + *q++ = (out_alpha[1] & 0xF0) | (out_alpha[0] >> 4); - // XXX not sure if more than one rect can really be encoded.. // 12 bytes per rect - for (object_id = 0; object_id < rects; object_id++) { - int x2 = h->rects[object_id]->x + h->rects[object_id]->w - 1; - int y2 = h->rects[object_id]->y + h->rects[object_id]->h - 1; - - *q++ = 0x05; - // x1 x2 -> 6 nibbles - *q++ = h->rects[object_id]->x >> 4; - *q++ = (h->rects[object_id]->x << 4) | ((x2 >> 8) & 0xf); - *q++ = x2; - // y1 y2 -> 6 nibbles - *q++ = h->rects[object_id]->y >> 4; - *q++ = (h->rects[object_id]->y << 4) | ((y2 >> 8) & 0xf); - *q++ = y2; - - *q++ = 0x06; - // offset1, offset2 - bytestream_put_be16(&q, offset1[object_id]); - bytestream_put_be16(&q, offset2[object_id]); - } + 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++ = 0x01; // start command *q++ = 0xff; // terminating command @@ -201,7 +378,41 @@ static int encode_dvd_subtitles(uint8_t *outbuf, int outbuf_size, bytestream_put_be16(&qq, q - outbuf); av_log(NULL, AV_LOG_DEBUG, "subtitle_packet size=%td\n", q - outbuf); - return 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'); + + if ((ret = av_bprint_finalize(&extradata, (char **)&avctx->extradata)) < 0) + return ret; + avctx->extradata_size = extradata.len; + + return 0; } static int dvdsub_encode(AVCodecContext *avctx, @@ -211,7 +422,7 @@ static int dvdsub_encode(AVCodecContext *avctx, AVSubtitle *sub = data; int ret; - ret = encode_dvd_subtitles(buf, buf_size, sub); + ret = encode_dvd_subtitles(avctx, buf, buf_size, sub); return ret; } @@ -219,6 +430,8 @@ AVCodec ff_dvdsub_encoder = { .name = "dvdsub", .type = AVMEDIA_TYPE_SUBTITLE, .id = AV_CODEC_ID_DVD_SUBTITLE, + .init = dvdsub_init, .encode = dvdsub_encode, .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"), + .priv_data_size = sizeof(DVDSubtitleContext), }; |
