diff options
Diffstat (limited to 'libavcodec/movtextenc.c')
-rw-r--r-- | libavcodec/movtextenc.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c new file mode 100644 index 0000000..d795e31 --- /dev/null +++ b/libavcodec/movtextenc.c @@ -0,0 +1,415 @@ +/* + * 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 { + AVCodecContext *avctx; + + 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; + s->avctx = avctx; + + 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 if (!s->style_attributes_temp) { + av_log(s->avctx, AV_LOG_WARNING, "Ignoring unmatched close tag\n"); + return; + } 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, +}; |