[FFmpeg-devel] [PATCH] movtextenc.c: Add support for text highlighting
Niklesh Lalwani
niklesh.lalwani at iitb.ac.in
Mon Jul 20 10:12:24 CEST 2015
From: Niklesh <niklesh.lalwani at iitb.ac.in>
This patch adds support for secondary color changes through highlight and hilightcolor box.
The code is also reorganised to make it easier to read and maintain.
Signed-off-by: Niklesh <niklesh.lalwani at iitb.ac.in>
---
libavcodec/movtextenc.c | 164 ++++++++++++++++++++++++++++++++++++------------
1 file changed, 125 insertions(+), 39 deletions(-)
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c
index 91b73ed..3219858 100644
--- a/libavcodec/movtextenc.c
+++ b/libavcodec/movtextenc.c
@@ -35,6 +35,10 @@
#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 {
@@ -44,14 +48,23 @@ typedef struct {
} 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 style_box_flag;
- uint32_t tsmb_size;
- uint32_t tsmb_type;
+ uint8_t box_flags;
uint16_t style_entries;
uint16_t style_fontID;
uint8_t style_fontsize;
@@ -59,6 +72,82 @@ typedef struct {
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)
{
@@ -116,13 +205,13 @@ 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
+ 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->style_box_flag = 0;
+ s->box_flags &= ~STYL_BOX;
return;
}
@@ -132,12 +221,11 @@ static void mov_text_style_cb(void *priv, const char style, int close)
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->style_box_flag = 0;
+ s->box_flags &= ~STYL_BOX;
return;
}
@@ -166,8 +254,9 @@ static void mov_text_style_cb(void *priv, const char style, int close)
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->style_box_flag = 0;
+ s->box_flags &= ~STYL_BOX;
return;
}
@@ -187,7 +276,26 @@ static void mov_text_style_cb(void *priv, const char style, int close)
s->style_attributes_temp->style_start = AV_RB16(&s->text_pos);
}
}
- s->style_box_flag = 1;
+ 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)
@@ -208,6 +316,7 @@ 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,
@@ -215,13 +324,13 @@ static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf,
{
MovTextContext *s = avctx->priv_data;
ASSDialog *dialog;
- int i, j, num, length;
+ int i, num, length;
+ size_t j;
s->text_pos = 0;
s->count = 0;
- s->style_box_flag = 0;
+ s->box_flags = 0;
s->style_entries = 0;
-
for (i = 0; i < sub->num_rects; i++) {
if (sub->rects[i]->type != SUBTITLE_ASS) {
@@ -233,32 +342,9 @@ 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_any(&s->buffer, &s->tsmb_size, 4);
- av_bprint_append_any(&s->buffer, &s->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);
- }
- for (j = 0; j < s->count; j++) {
- av_freep(&s->style_attributes[j]);
- }
- av_freep(&s->style_attributes);
- av_freep(&s->style_attributes_temp);
+
+ for (j = 0; j < box_count; j++) {
+ box_types[j].encode(s, box_types[j].type);
}
}
--
1.9.1
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