/* * 3GPP TS 26.245 Timed Text encoder * Copyright (c) 2012 Philip Langdale * * 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 #include "avcodec.h" #include "libavutil/opt.h" #include "libavutil/avstring.h" #include "libavutil/intreadwrite.h" #include "libavutil/mem.h" #include "libavutil/common.h" #include "ass_split.h" #include "ass.h" #include "bytestream.h" #include "codec_internal.h" #define STYLE_FLAG_BOLD (1<<0) #define STYLE_FLAG_ITALIC (1<<1) #define STYLE_FLAG_UNDERLINE (1<<2) #define STYLE_RECORD_SIZE 12 #define SIZE_ADD 10 #define STYL_BOX (1<<0) #define HLIT_BOX (1<<1) #define HCLR_BOX (1<<2) #define DEFAULT_STYLE_FONT_ID 0x01 #define DEFAULT_STYLE_FONTSIZE 0x12 #define DEFAULT_STYLE_COLOR 0xffffffff #define DEFAULT_STYLE_FLAG 0x00 #define BGR_TO_RGB(c) (((c) & 0xff) << 16 | ((c) & 0xff00) | (((uint32_t)(c) >> 16) & 0xff)) #define FONTSIZE_SCALE(s,fs) ((fs) * (s)->font_scale_factor + 0.5) #define av_bprint_append_any(buf, data, size) av_bprint_append_data(buf, ((const char*)data), size) typedef struct { uint16_t style_start; uint16_t style_end; uint8_t style_flag; uint16_t style_fontID; uint8_t style_fontsize; uint32_t style_color; } StyleBox; typedef struct { uint16_t start; uint16_t end; } HighlightBox; typedef struct { uint32_t color; } HilightcolorBox; typedef struct { AVClass *class; AVCodecContext *avctx; ASSSplitContext *ass_ctx; ASSStyle *ass_dialog_style; StyleBox *style_attributes; unsigned count; unsigned style_attributes_bytes_allocated; StyleBox style_attributes_temp; AVBPrint buffer; HighlightBox hlit; HilightcolorBox hclr; uint8_t box_flags; StyleBox d; uint16_t text_pos; char **fonts; int font_count; double font_scale_factor; int frame_height; } MovTextContext; typedef struct { void (*encode)(MovTextContext *s); } Box; static void mov_text_cleanup(MovTextContext *s) { s->count = 0; s->style_attributes_temp = s->d; } static void encode_styl(MovTextContext *s) { if ((s->box_flags & STYL_BOX) && s->count) { uint8_t buf[12], *p = buf; bytestream_put_be32(&p, s->count * STYLE_RECORD_SIZE + SIZE_ADD); bytestream_put_be32(&p, MKBETAG('s','t','y','l')); bytestream_put_be16(&p, s->count); /*The above three attributes are hard coded for now but will come from ASS style in the future*/ av_bprint_append_any(&s->buffer, buf, 10); for (unsigned j = 0; j < s->count; j++) { const StyleBox *style = &s->style_attributes[j]; p = buf; bytestream_put_be16(&p, style->style_start); bytestream_put_be16(&p, style->style_end); bytestream_put_be16(&p, style->style_fontID); bytestream_put_byte(&p, style->style_flag); bytestream_put_byte(&p, style->style_fontsize); bytestream_put_be32(&p, style->style_color); av_bprint_append_any(&s->buffer, buf, 12); } } mov_text_cleanup(s); } static void encode_hlit(MovTextContext *s) { if (s->box_flags & HLIT_BOX) { uint8_t buf[12], *p = buf; bytestream_put_be32(&p, 12); bytestream_put_be32(&p, MKBETAG('h','l','i','t')); bytestream_put_be16(&p, s->hlit.start); bytestream_put_be16(&p, s->hlit.end); av_bprint_append_any(&s->buffer, buf, 12); } } static void encode_hclr(MovTextContext *s) { if (s->box_flags & HCLR_BOX) { uint8_t buf[12], *p = buf; bytestream_put_be32(&p, 12); bytestream_put_be32(&p, MKBETAG('h','c','l','r')); bytestream_put_be32(&p, s->hclr.color); av_bprint_append_any(&s->buffer, buf, 12); } } static const Box box_types[] = { { encode_styl }, { encode_hlit }, { encode_hclr }, }; const static size_t box_count = FF_ARRAY_ELEMS(box_types); static int mov_text_encode_close(AVCodecContext *avctx) { MovTextContext *s = avctx->priv_data; ff_ass_split_free(s->ass_ctx); av_freep(&s->style_attributes); av_freep(&s->fonts); av_bprint_finalize(&s->buffer, NULL); return 0; } static int encode_sample_description(AVCodecContext *avctx) { ASS *ass; ASSStyle *style; int i, j; uint32_t back_color = 0; int font_names_total_len = 0; MovTextContext *s = avctx->priv_data; uint8_t buf[30], *p = buf; // 0x00, 0x00, 0x00, 0x00, // uint32_t displayFlags // 0x01, // int8_t horizontal-justification // 0xFF, // int8_t vertical-justification // 0x00, 0x00, 0x00, 0x00, // uint8_t background-color-rgba[4] // BoxRecord { // 0x00, 0x00, // int16_t top // 0x00, 0x00, // int16_t left // 0x00, 0x00, // int16_t bottom // 0x00, 0x00, // int16_t right // }; // StyleRecord { // 0x00, 0x00, // uint16_t startChar // 0x00, 0x00, // uint16_t endChar // 0x00, 0x01, // uint16_t font-ID // 0x00, // uint8_t face-style-flags // 0x12, // uint8_t font-size // 0xFF, 0xFF, 0xFF, 0xFF, // uint8_t text-color-rgba[4] // }; // FontTableBox { // 0x00, 0x00, 0x00, 0x12, // uint32_t size // 'f', 't', 'a', 'b', // uint8_t name[4] // 0x00, 0x01, // uint16_t entry-count // FontRecord { // 0x00, 0x01, // uint16_t font-ID // 0x05, // uint8_t font-name-length // 'S', 'e', 'r', 'i', 'f',// uint8_t font[font-name-length] // }; // }; // Populate sample description from ASS header ass = (ASS*)s->ass_ctx; // Compute font scaling factor based on (optionally) provided // output video height and ASS script play_res_y if (s->frame_height && ass->script_info.play_res_y) s->font_scale_factor = (double)s->frame_height / ass->script_info.play_res_y; else s->font_scale_factor = 1; style = ff_ass_style_get(s->ass_ctx, "Default"); if (!style && ass->styles_count) { style = &ass->styles[0]; } s->d.style_fontID = DEFAULT_STYLE_FONT_ID; s->d.style_fontsize = DEFAULT_STYLE_FONTSIZE; s->d.style_color = DEFAULT_STYLE_COLOR; s->d.style_flag = DEFAULT_STYLE_FLAG; if (style) { s->d.style_fontsize = FONTSIZE_SCALE(s, style->font_size); s->d.style_color = BGR_TO_RGB(style->primary_color & 0xffffff) << 8 | 255 - ((uint32_t)style->primary_color >> 24); s->d.style_flag = (!!style->bold * STYLE_FLAG_BOLD) | (!!style->italic * STYLE_FLAG_ITALIC) | (!!style->underline * STYLE_FLAG_UNDERLINE); back_color = (BGR_TO_RGB(style->back_color & 0xffffff) << 8) | (255 - ((uint32_t)style->back_color >> 24)); } bytestream_put_be32(&p, 0); // displayFlags bytestream_put_be16(&p, 0x01FF); // horizontal/vertical justification (2x int8_t) bytestream_put_be32(&p, back_color); bytestream_put_be64(&p, 0); // BoxRecord - 4xint16_t: top, left, bottom, right // StyleRecord { bytestream_put_be16(&p, s->d.style_start); bytestream_put_be16(&p, s->d.style_end); bytestream_put_be16(&p, s->d.style_fontID); bytestream_put_byte(&p, s->d.style_flag); bytestream_put_byte(&p, s->d.style_fontsize); bytestream_put_be32(&p, s->d.style_color); // }; av_bprint_append_any(&s->buffer, buf, 30); // Build font table // We can't build a complete font table since that would require // scanning all dialogs first. But we can at least fill in what // is avaiable in the ASS header if (style && ass->styles_count) { // Find unique font names if (style->font_name) { av_dynarray_add(&s->fonts, &s->font_count, style->font_name); font_names_total_len += strlen(style->font_name); } for (i = 0; i < ass->styles_count; i++) { int found = 0; if (!ass->styles[i].font_name) continue; for (j = 0; j < s->font_count; j++) { if (!strcmp(s->fonts[j], ass->styles[i].font_name)) { found = 1; break; } } if (!found) { av_dynarray_add(&s->fonts, &s->font_count, ass->styles[i].font_name); font_names_total_len += strlen(ass->styles[i].font_name); } } } else av_dynarray_add(&s->fonts, &s->font_count, (char*)"Serif"); // FontTableBox { p = buf; bytestream_put_be32(&p, SIZE_ADD + 3 * s->font_count + font_names_total_len); // Size bytestream_put_be32(&p, MKBETAG('f','t','a','b')); bytestream_put_be16(&p, s->font_count); av_bprint_append_any(&s->buffer, buf, 10); // FontRecord { for (i = 0; i < s->font_count; i++) { size_t len = strlen(s->fonts[i]); p = buf; bytestream_put_be16(&p, i + 1); //fontID bytestream_put_byte(&p, len); av_bprint_append_any(&s->buffer, buf, 3); av_bprint_append_any(&s->buffer, s->fonts[i], len); } // }; // }; if (!av_bprint_is_complete(&s->buffer)) { return AVERROR(ENOMEM); } avctx->extradata_size = s->buffer.len; avctx->extradata = av_mallocz(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!avctx->extradata) { return AVERROR(ENOMEM); } memcpy(avctx->extradata, s->buffer.str, avctx->extradata_size); av_bprint_clear(&s->buffer); return 0; } static av_cold int mov_text_encode_init(AVCodecContext *avctx) { int ret; MovTextContext *s = avctx->priv_data; s->avctx = avctx; av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED); s->ass_ctx = ff_ass_split(avctx->subtitle_header); if (!s->ass_ctx) return AVERROR_INVALIDDATA; ret = encode_sample_description(avctx); if (ret < 0) return ret; return 0; } // Start a new style box if needed static int mov_text_style_start(MovTextContext *s) { // there's an existing style entry if (s->style_attributes_temp.style_start == s->text_pos) // Still at same text pos, use same entry return 1; if (s->style_attributes_temp.style_flag != s->d.style_flag || s->style_attributes_temp.style_color != s->d.style_color || s->style_attributes_temp.style_fontID != s->d.style_fontID || s->style_attributes_temp.style_fontsize != s->d.style_fontsize) { StyleBox *tmp; // last style != defaults, end the style entry and start a new one if (s->count + 1 > FFMIN(SIZE_MAX / sizeof(*s->style_attributes), UINT16_MAX) || !(tmp = av_fast_realloc(s->style_attributes, &s->style_attributes_bytes_allocated, (s->count + 1) * sizeof(*s->style_attributes)))) { mov_text_cleanup(s); av_bprint_clear(&s->buffer); s->box_flags &= ~STYL_BOX; return 0; } s->style_attributes = tmp; s->style_attributes_temp.style_end = s->text_pos; s->style_attributes[s->count++] = s->style_attributes_temp; s->box_flags |= STYL_BOX; s->style_attributes_temp = s->d; s->style_attributes_temp.style_start = s->text_pos; } else { // style entry matches defaults, drop entry s->style_attributes_temp = s->d; s->style_attributes_temp.style_start = s->text_pos; } return 1; } static uint8_t mov_text_style_to_flag(const char style) { uint8_t style_flag = 0; switch (style){ case 'b': style_flag = STYLE_FLAG_BOLD; break; case 'i': style_flag = STYLE_FLAG_ITALIC; break; case 'u': style_flag = STYLE_FLAG_UNDERLINE; break; } return style_flag; } static void mov_text_style_set(MovTextContext *s, uint8_t style_flags) { if (!((s->style_attributes_temp.style_flag & style_flags) ^ style_flags)) { // setting flags that that are already set return; } if (mov_text_style_start(s)) s->style_attributes_temp.style_flag |= style_flags; } static void mov_text_style_cb(void *priv, const char style, int close) { MovTextContext *s = priv; uint8_t style_flag = mov_text_style_to_flag(style); if (!!(s->style_attributes_temp.style_flag & style_flag) != close) { // setting flag that is already set return; } if (mov_text_style_start(s)) { if (!close) s->style_attributes_temp.style_flag |= style_flag; else s->style_attributes_temp.style_flag &= ~style_flag; } } static void mov_text_color_set(MovTextContext *s, uint32_t color) { if ((s->style_attributes_temp.style_color & 0xffffff00) == color) { // color hasn't changed return; } if (mov_text_style_start(s)) s->style_attributes_temp.style_color = (color & 0xffffff00) | (s->style_attributes_temp.style_color & 0xff); } static void mov_text_color_cb(void *priv, unsigned int color, unsigned int color_id) { MovTextContext *s = priv; color = BGR_TO_RGB(color) << 8; if (color_id == 1) { //primary color changes mov_text_color_set(s, color); } else if (color_id == 2) { //secondary color changes if (!(s->box_flags & HCLR_BOX)) // Highlight alpha not set yet, use current primary alpha s->hclr.color = s->style_attributes_temp.style_color; if (!(s->box_flags & HLIT_BOX) || s->hlit.start == s->text_pos) { s->box_flags |= HCLR_BOX; s->box_flags |= HLIT_BOX; s->hlit.start = s->text_pos; s->hclr.color = color | (s->hclr.color & 0xFF); } else //close tag s->hlit.end = s->text_pos; /* If there are more than one secondary color changes in ASS, take start of first section and end of last section. Movtext allows only one highlight box per sample. */ } // Movtext does not support changes to other color_id (outline, background) } static void mov_text_alpha_set(MovTextContext *s, uint8_t alpha) { if ((s->style_attributes_temp.style_color & 0xff) == alpha) { // color hasn't changed return; } if (mov_text_style_start(s)) s->style_attributes_temp.style_color = (s->style_attributes_temp.style_color & 0xffffff00) | alpha; } static void mov_text_alpha_cb(void *priv, int alpha, int alpha_id) { MovTextContext *s = priv; alpha = 255 - alpha; if (alpha_id == 1) // primary alpha changes mov_text_alpha_set(s, alpha); else if (alpha_id == 2) { //secondary alpha changes if (!(s->box_flags & HCLR_BOX)) // Highlight color not set yet, use current primary color s->hclr.color = s->style_attributes_temp.style_color; if (!(s->box_flags & HLIT_BOX) || s->hlit.start == s->text_pos) { s->box_flags |= HCLR_BOX; s->box_flags |= HLIT_BOX; s->hlit.start = s->text_pos; s->hclr.color = (s->hclr.color & 0xffffff00) | alpha; } else //close tag s->hlit.end = s->text_pos; } // Movtext does not support changes to other alpha_id (outline, background) } static uint16_t find_font_id(MovTextContext *s, const char *name) { if (!name) return 1; for (int i = 0; i < s->font_count; i++) { if (!strcmp(name, s->fonts[i])) return i + 1; } return 1; } static void mov_text_font_name_set(MovTextContext *s, const char *name) { int fontID = find_font_id(s, name); if (s->style_attributes_temp.style_fontID == fontID) { // color hasn't changed return; } if (mov_text_style_start(s)) s->style_attributes_temp.style_fontID = fontID; } static void mov_text_font_name_cb(void *priv, const char *name) { mov_text_font_name_set((MovTextContext*)priv, name); } static void mov_text_font_size_set(MovTextContext *s, int size) { size = FONTSIZE_SCALE(s, size); if (s->style_attributes_temp.style_fontsize == size) { // color hasn't changed return; } if (mov_text_style_start(s)) s->style_attributes_temp.style_fontsize = size; } static void mov_text_font_size_cb(void *priv, int size) { mov_text_font_size_set((MovTextContext*)priv, size); } static void mov_text_end_cb(void *priv) { // End of text, close any open style record mov_text_style_start((MovTextContext*)priv); } static void mov_text_ass_style_set(MovTextContext *s, ASSStyle *style) { uint8_t style_flags, alpha; uint32_t color; if (style) { style_flags = (!!style->bold * STYLE_FLAG_BOLD) | (!!style->italic * STYLE_FLAG_ITALIC) | (!!style->underline * STYLE_FLAG_UNDERLINE); mov_text_style_set(s, style_flags); color = BGR_TO_RGB(style->primary_color & 0xffffff) << 8; mov_text_color_set(s, color); alpha = 255 - ((uint32_t)style->primary_color >> 24); mov_text_alpha_set(s, alpha); mov_text_font_size_set(s, style->font_size); mov_text_font_name_set(s, style->font_name); } else { // End current style record, go back to defaults mov_text_style_start(s); } } static void mov_text_dialog(MovTextContext *s, ASSDialog *dialog) { ASSStyle *style = ff_ass_style_get(s->ass_ctx, dialog->style); s->ass_dialog_style = style; mov_text_ass_style_set(s, style); } static void mov_text_cancel_overrides_cb(void *priv, const char *style_name) { MovTextContext *s = priv; ASSStyle *style; if (!style_name || !*style_name) style = s->ass_dialog_style; else style= ff_ass_style_get(s->ass_ctx, style_name); mov_text_ass_style_set(s, style); } static unsigned utf8_strlen(const char *text, int len) { unsigned i = 0, ret = 0; while (i < len) { char c = text[i]; if ((c & 0x80) == 0) i += 1; else if ((c & 0xE0) == 0xC0) i += 2; else if ((c & 0xF0) == 0xE0) i += 3; else if ((c & 0xF8) == 0xF0) i += 4; else return 0; ret++; } return ret; } static void mov_text_text_cb(void *priv, const char *text, int len) { unsigned utf8_len = utf8_strlen(text, len); MovTextContext *s = priv; av_bprint_append_data(&s->buffer, text, len); // If it's not utf-8, just use the byte length s->text_pos += utf8_len ? utf8_len : len; } static void mov_text_new_line_cb(void *priv, int forced) { MovTextContext *s = priv; s->text_pos += 1; av_bprint_chars(&s->buffer, '\n', 1); } static const ASSCodesCallbacks mov_text_callbacks = { .text = mov_text_text_cb, .new_line = mov_text_new_line_cb, .style = mov_text_style_cb, .color = mov_text_color_cb, .alpha = mov_text_alpha_cb, .font_name = mov_text_font_name_cb, .font_size = mov_text_font_size_cb, .cancel_overrides = mov_text_cancel_overrides_cb, .end = mov_text_end_cb, }; static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub) { MovTextContext *s = avctx->priv_data; ASSDialog *dialog; int i, length; s->text_pos = 0; s->count = 0; s->box_flags = 0; av_bprint_clear(&s->buffer); for (i = 0; i < sub->num_rects; i++) { const char *ass = sub->rects[i]->ass; if (sub->rects[i]->type != SUBTITLE_ASS) { av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); return AVERROR(EINVAL); } dialog = ff_ass_split_dialog(s->ass_ctx, ass); if (!dialog) return AVERROR(ENOMEM); mov_text_dialog(s, dialog); ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text); ff_ass_free_dialog(&dialog); } if (s->buffer.len > UINT16_MAX) return AVERROR(ERANGE); AV_WB16(buf, s->buffer.len); buf += 2; for (size_t j = 0; j < box_count; j++) box_types[j].encode(s); if (!av_bprint_is_complete(&s->buffer)) return AVERROR(ENOMEM); if (!s->buffer.len) return 0; if (s->buffer.len > bufsize - 3) { av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); return AVERROR_BUFFER_TOO_SMALL; } memcpy(buf, s->buffer.str, s->buffer.len); length = s->buffer.len + 2; return length; } #define OFFSET(x) offsetof(MovTextContext, x) #define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_SUBTITLE_PARAM static const AVOption options[] = { { "height", "Frame height, usually video height", OFFSET(frame_height), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS }, { NULL }, }; static const AVClass mov_text_encoder_class = { .class_name = "MOV text enoder", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; const FFCodec ff_movtext_encoder = { .p.name = "mov_text", CODEC_LONG_NAME("3GPP Timed Text subtitle"), .p.type = AVMEDIA_TYPE_SUBTITLE, .p.id = AV_CODEC_ID_MOV_TEXT, .priv_data_size = sizeof(MovTextContext), .p.priv_class = &mov_text_encoder_class, .init = mov_text_encode_init, FF_CODEC_ENCODE_SUB_CB(mov_text_encode_frame), .close = mov_text_encode_close, .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, };