summaryrefslogtreecommitdiff
path: root/libavcodec/movtextenc.c
diff options
context:
space:
mode:
Diffstat (limited to 'libavcodec/movtextenc.c')
-rw-r--r--libavcodec/movtextenc.c409
1 files changed, 409 insertions, 0 deletions
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
new file mode 100644
index 0000000000..20e01e206e
--- /dev/null
+++ b/libavcodec/movtextenc.c
@@ -0,0 +1,409 @@
+/*
+ * 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,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 13:29:57 +0000