/* * 3GPP TS 26.245 Timed Text encoder * Copyright (c) 2012 Philip Langdale <philipl@overt.org> * * 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 <stdarg.h> #include "avcodec.h" #include "libavutil/avassert.h" #include "libavutil/avstring.h" #include "libavutil/intreadwrite.h" #include "libavutil/mem.h" #include "libavutil/common.h" #include "ass_split.h" #include "ass.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 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; } StyleBox; typedef struct { uint16_t start; uint16_t end; } HighlightBox; typedef struct { uint32_t color; } HilightcolorBox; typedef struct { ASSSplitContext *ass_ctx; AVBPrint buffer; StyleBox **style_attributes; StyleBox *style_attributes_temp; HighlightBox hlit; HilightcolorBox hclr; int count; uint8_t box_flags; uint16_t style_entries; uint16_t style_fontID; uint8_t style_fontsize; uint32_t style_color; uint16_t text_pos; } MovTextContext; typedef struct { uint32_t type; void (*encode)(MovTextContext *s, uint32_t tsmb_type); } Box; static void mov_text_cleanup(MovTextContext *s) { int j; if (s->box_flags & STYL_BOX) { for (j = 0; j < s->count; j++) { av_freep(&s->style_attributes[j]); } av_freep(&s->style_attributes); } } static void encode_styl(MovTextContext *s, uint32_t tsmb_type) { int j; uint32_t tsmb_size; if (s->box_flags & STYL_BOX) { tsmb_size = s->count * STYLE_RECORD_SIZE + SIZE_ADD; tsmb_size = AV_RB32(&tsmb_size); s->style_entries = AV_RB16(&s->count); s->style_fontID = 0x00 | 0x01<<8; s->style_fontsize = 0x12; s->style_color = MKTAG(0xFF, 0xFF, 0xFF, 0xFF); /*The above three attributes are hard coded for now but will come from ASS style in the future*/ av_bprint_append_any(&s->buffer, &tsmb_size, 4); av_bprint_append_any(&s->buffer, &tsmb_type, 4); av_bprint_append_any(&s->buffer, &s->style_entries, 2); for (j = 0; j < s->count; j++) { av_bprint_append_any(&s->buffer, &s->style_attributes[j]->style_start, 2); av_bprint_append_any(&s->buffer, &s->style_attributes[j]->style_end, 2); av_bprint_append_any(&s->buffer, &s->style_fontID, 2); av_bprint_append_any(&s->buffer, &s->style_attributes[j]->style_flag, 1); av_bprint_append_any(&s->buffer, &s->style_fontsize, 1); av_bprint_append_any(&s->buffer, &s->style_color, 4); } mov_text_cleanup(s); } } static void encode_hlit(MovTextContext *s, uint32_t tsmb_type) { uint32_t tsmb_size; if (s->box_flags & HLIT_BOX) { tsmb_size = 12; tsmb_size = AV_RB32(&tsmb_size); av_bprint_append_any(&s->buffer, &tsmb_size, 4); av_bprint_append_any(&s->buffer, &tsmb_type, 4); av_bprint_append_any(&s->buffer, &s->hlit.start, 2); av_bprint_append_any(&s->buffer, &s->hlit.end, 2); } } static void encode_hclr(MovTextContext *s, uint32_t tsmb_type) { uint32_t tsmb_size; if (s->box_flags & HCLR_BOX) { tsmb_size = 12; tsmb_size = AV_RB32(&tsmb_size); av_bprint_append_any(&s->buffer, &tsmb_size, 4); av_bprint_append_any(&s->buffer, &tsmb_type, 4); av_bprint_append_any(&s->buffer, &s->hclr.color, 4); } } static const Box box_types[] = { { MKTAG('s','t','y','l'), encode_styl }, { MKTAG('h','l','i','t'), encode_hlit }, { MKTAG('h','c','l','r'), encode_hclr }, }; const static size_t box_count = FF_ARRAY_ELEMS(box_types); static av_cold int mov_text_encode_init(AVCodecContext *avctx) { /* * For now, we'll use a fixed default style. When we add styling * support, this will be generated from the ASS style. */ static const uint8_t text_sample_entry[] = { 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] // }; // }; }; MovTextContext *s = avctx->priv_data; avctx->extradata_size = sizeof text_sample_entry; avctx->extradata = av_mallocz(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!avctx->extradata) return AVERROR(ENOMEM); av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED); memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size); s->ass_ctx = ff_ass_split(avctx->subtitle_header); return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; } static void mov_text_style_cb(void *priv, const char style, int close) { MovTextContext *s = priv; if (!close) { if (!(s->box_flags & STYL_BOX)) { //first style entry s->style_attributes_temp = av_malloc(sizeof(*s->style_attributes_temp)); if (!s->style_attributes_temp) { av_bprint_clear(&s->buffer); s->box_flags &= ~STYL_BOX; return; } s->style_attributes_temp->style_flag = 0; s->style_attributes_temp->style_start = AV_RB16(&s->text_pos); } else { if (s->style_attributes_temp->style_flag) { //break the style record here and start a new one s->style_attributes_temp->style_end = AV_RB16(&s->text_pos); av_dynarray_add(&s->style_attributes, &s->count, s->style_attributes_temp); s->style_attributes_temp = av_malloc(sizeof(*s->style_attributes_temp)); if (!s->style_attributes_temp) { mov_text_cleanup(s); av_bprint_clear(&s->buffer); s->box_flags &= ~STYL_BOX; return; } s->style_attributes_temp->style_flag = s->style_attributes[s->count - 1]->style_flag; s->style_attributes_temp->style_start = AV_RB16(&s->text_pos); } else { s->style_attributes_temp->style_flag = 0; s->style_attributes_temp->style_start = AV_RB16(&s->text_pos); } } switch (style){ case 'b': s->style_attributes_temp->style_flag |= STYLE_FLAG_BOLD; break; case 'i': s->style_attributes_temp->style_flag |= STYLE_FLAG_ITALIC; break; case 'u': s->style_attributes_temp->style_flag |= STYLE_FLAG_UNDERLINE; break; } } else { s->style_attributes_temp->style_end = AV_RB16(&s->text_pos); av_dynarray_add(&s->style_attributes, &s->count, s->style_attributes_temp); s->style_attributes_temp = av_malloc(sizeof(*s->style_attributes_temp)); if (!s->style_attributes_temp) { mov_text_cleanup(s); av_bprint_clear(&s->buffer); s->box_flags &= ~STYL_BOX; return; } s->style_attributes_temp->style_flag = s->style_attributes[s->count - 1]->style_flag; switch (style){ case 'b': s->style_attributes_temp->style_flag &= ~STYLE_FLAG_BOLD; break; case 'i': s->style_attributes_temp->style_flag &= ~STYLE_FLAG_ITALIC; break; case 'u': s->style_attributes_temp->style_flag &= ~STYLE_FLAG_UNDERLINE; break; } if (s->style_attributes_temp->style_flag) { //start of new style record s->style_attributes_temp->style_start = AV_RB16(&s->text_pos); } } s->box_flags |= STYL_BOX; } static void mov_text_color_cb(void *priv, unsigned int color, unsigned int color_id) { MovTextContext *s = priv; if (color_id == 2) { //secondary color changes if (s->box_flags & HLIT_BOX) { //close tag s->hlit.end = AV_RB16(&s->text_pos); } else { s->box_flags |= HCLR_BOX; s->box_flags |= HLIT_BOX; s->hlit.start = AV_RB16(&s->text_pos); s->hclr.color = color | (0xFF << 24); //set alpha value to FF } } /* 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. */ } static void mov_text_text_cb(void *priv, const char *text, int len) { MovTextContext *s = priv; av_bprint_append_data(&s->buffer, text, len); s->text_pos += len; } static void mov_text_new_line_cb(void *priv, int forced) { MovTextContext *s = priv; av_bprint_append_data(&s->buffer, "\n", 1); s->text_pos += 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, }; 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; size_t j; s->text_pos = 0; s->count = 0; s->box_flags = 0; s->style_entries = 0; 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(ENOSYS); } #if FF_API_ASS_TIMING if (!strncmp(ass, "Dialogue: ", 10)) { int num; dialog = ff_ass_split_dialog(s->ass_ctx, ass, 0, &num); for (; dialog && num--; dialog++) { ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text); } } else { #endif dialog = ff_ass_split_dialog2(s->ass_ctx, ass); if (!dialog) return AVERROR(ENOMEM); ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text); ff_ass_free_dialog(&dialog); #if FF_API_ASS_TIMING } #endif for (j = 0; j < box_count; j++) { box_types[j].encode(s, box_types[j].type); } } AV_WB16(buf, s->text_pos); buf += 2; if (!av_bprint_is_complete(&s->buffer)) { length = AVERROR(ENOMEM); goto exit; } if (!s->buffer.len) { length = 0; goto exit; } if (s->buffer.len > bufsize - 3) { av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); length = AVERROR(EINVAL); goto exit; } memcpy(buf, s->buffer.str, s->buffer.len); length = s->buffer.len + 2; exit: av_bprint_clear(&s->buffer); return length; } static int mov_text_encode_close(AVCodecContext *avctx) { MovTextContext *s = avctx->priv_data; ff_ass_split_free(s->ass_ctx); av_bprint_finalize(&s->buffer, NULL); return 0; } AVCodec ff_movtext_encoder = { .name = "mov_text", .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"), .type = AVMEDIA_TYPE_SUBTITLE, .id = AV_CODEC_ID_MOV_TEXT, .priv_data_size = sizeof(MovTextContext), .init = mov_text_encode_init, .encode_sub = mov_text_encode_frame, .close = mov_text_encode_close, };