[FFmpeg-devel] [PATCH 2/2] movtextenc.c: Support for Bold, Italic and Underlined styles
Niklesh Lalwani
niklesh.lalwani at iitb.ac.in
Wed Jun 17 17:13:26 CEST 2015
From: Niklesh <niklesh.lalwani at iitb.ac.in>
Support for Bold, Italic and Underlined styles. The style information is appended into the buffer after the text. Dynarray is used to account for multiple style records. Tested on QuickTime OSX and iPhone.
Signed-off-by: Niklesh <niklesh.lalwani at iitb.ac.in>
---
libavcodec/movtextenc.c | 165 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 145 insertions(+), 20 deletions(-)
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
index 1b8f454..56c599d 100644
--- a/libavcodec/movtextenc.c
+++ b/libavcodec/movtextenc.c
@@ -24,14 +24,38 @@
#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
+#define STYLE_FLAG_ITALIC 2
+#define STYLE_FLAG_UNDERLINE 4
+#define STYLE_RECORD_SIZE 12
+#define SIZE_ADD 10
+
+
+typedef struct {
+ uint16_t style_start;
+ uint16_t style_end;
+ uint8_t style_flag;
+} StyleBox;
+
typedef struct {
ASSSplitContext *ass_ctx;
- char buffer[2048];
- char *ptr;
- char *end;
+ AVBPrint buffer;
+ StyleBox **style_attributes;
+ StyleBox *style_attributes_temp;
+ int count;
+ uint8_t style_box_flag;
+ uint32_t tsmb_size;
+ uint32_t tsmb_type;
+ uint16_t style_entries;
+ uint16_t style_fontID;
+ uint8_t style_fontsize;
+ uint32_t style_color;
+ uint16_t text_pos;
} MovTextContext;
@@ -79,32 +103,98 @@ static av_cold int mov_text_encode_init(AVCodecContext *avctx)
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->style_box_flag == 0) { //first style entry
+
+ s->style_attributes_temp = av_malloc(sizeof(StyleBox));
+ if (!s->style_attributes_temp)
+ return AVERROR(ENOMEM);
+
+ 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(StyleBox));
+ if (!s->style_attributes_temp)
+ return AVERROR(ENOMEM);
+
+ 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(StyleBox));
+ if (!s->style_attributes_temp)
+ return AVERROR(ENOMEM);
+
+ 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->style_box_flag = 1;
+}
+
static void mov_text_text_cb(void *priv, const char *text, int len)
{
MovTextContext *s = priv;
- av_assert0(s->end >= s->ptr);
- av_strlcpy(s->ptr, text, FFMIN(s->end - s->ptr, len + 1));
- s->ptr += FFMIN(s->end - s->ptr, len);
+ 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_assert0(s->end >= s->ptr);
- av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2));
- if (s->end > s->ptr)
- s->ptr++;
+ av_bprint_append_data(&s->buffer, "\n", 2);
+ s->text_pos += 2;
}
static const ASSCodesCallbacks mov_text_callbacks = {
.text = mov_text_text_cb,
.new_line = mov_text_new_line_cb,
+ .style = mov_text_style_cb,
};
static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
@@ -112,10 +202,12 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
{
MovTextContext *s = avctx->priv_data;
ASSDialog *dialog;
- int i, len, num;
+ int i, j, num, length;
- s->ptr = s->buffer;
- s->end = s->ptr + sizeof(s->buffer);
+ s->text_pos = 0;
+ s->count = 0;
+ s->style_box_flag = 0;
+ s->style_entries = 0;
for (i = 0; i < sub->num_rects; i++) {
@@ -128,28 +220,61 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
for (; dialog && num--; dialog++) {
ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text);
}
+ if (s->style_box_flag) {
+ s->tsmb_size = s->count * STYLE_RECORD_SIZE + SIZE_ADD; //size of one style record is 12 bytes
+ s->tsmb_size = AV_RB32(&s->tsmb_size);
+ s->tsmb_type = MKTAG('s','t','y','l');
+ 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_data(&s->buffer, &s->tsmb_size, 4);
+ av_bprint_append_data(&s->buffer, &s->tsmb_type, 4);
+ av_bprint_append_data(&s->buffer, &s->style_entries, 2);
+ for (j = 0; j < s->count; j++) {
+ av_bprint_append_data(&s->buffer, &s->style_attributes[j]->style_start, 2);
+ av_bprint_append_data(&s->buffer, &s->style_attributes[j]->style_end, 2);
+ av_bprint_append_data(&s->buffer, &s->style_fontID, 2);
+ av_bprint_append_data(&s->buffer, &s->style_attributes[j]->style_flag, 1);
+ av_bprint_append_data(&s->buffer, &s->style_fontsize, 1);
+ av_bprint_append_data(&s->buffer, &s->style_color, 4);
+ }
+ for (j = 0; j < s->count; j++) {
+ av_freep(&s->style_attributes[j]);
+ }
+ av_freep(&s->style_attributes);
+ av_freep(&s->style_attributes_temp);
+ }
}
- if (s->ptr == s->buffer)
- return 0;
-
- AV_WB16(buf, strlen(s->buffer));
+ AV_WB16(buf, s->text_pos);
buf += 2;
- len = av_strlcpy(buf, s->buffer, bufsize - 2);
+ if (!av_bprint_is_complete(&s->buffer))
+ return AVERROR(ENOMEM);
+ if (!s->buffer.len)
+ return 0;
- if (len > bufsize-3) {
+ if (s->buffer.len > bufsize - 3) {
av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
return AVERROR(EINVAL);
}
- return len + 2;
+ memcpy(buf, s->buffer.str, s->buffer.len);
+ length = s->buffer.len + 2;
+
+ 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;
}
--
1.9.1
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