[FFmpeg-devel] [PATCH 2/2] movtextenc.c: Support for Bold, Italic and Underlined styles
Philip Langdale
philipl at overt.org
Sat Jun 20 19:55:24 CEST 2015
On Thu, 18 Jun 2015 22:20:05 +0530
Niklesh Lalwani <niklesh.lalwani at iitb.ac.in> wrote:
> Updated patch.
>
> Thanks,
> Niklesh
> From faae5cbec4772b81f124c09326010ddafc7aa780 Mon Sep 17 00:00:00 2001
> From: Niklesh <niklesh.lalwani at iitb.ac.in>
> Date: Thu, 18 Jun 2015 22:04:54 +0530
> Subject: [PATCH 2/2] movtextenc.c: Support for Bold, Italic and
> Underlined styles
>
> 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..1d38dda 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<<0)
> +#define STYLE_FLAG_ITALIC (1<<1)
> +#define STYLE_FLAG_UNDERLINE (1<<2)
> +#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(*s->style_attributes_temp));
> + 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(*s->style_attributes_temp));
> + 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(*s->style_attributes_temp));
> + 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);
> }
You need to call av_brpint_clear in eahc of these failure cases.
The normal pattern would be to set 'length' to the error code
and then 'goto exit;' which would ensure you always clear it.
Otherwise, on the next frame, it will still have all the old
data in it.
> - 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
>
--phil
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