[FFmpeg-devel] [PATCH] movtextdec.c: Add support for font names
Philip Langdale
philipl at overt.org
Wed Aug 5 22:32:56 CEST 2015
On Thu, 6 Aug 2015 00:12:07 +0530
Niklesh Lalwani <lalwani1994 at gmail.com> wrote:
> From 90f466bb6a5d3cd24d7ea4d9fd8a2915cc68cdb2 Mon Sep 17 00:00:00 2001
> From: Niklesh <niklesh.lalwani at iitb.ac.in>
> Date: Thu, 6 Aug 2015 00:06:15 +0530
> Subject: [PATCH] movtextdec.c: Add support for font names
>
> Signed-off-by: Niklesh <niklesh.lalwani at iitb.ac.in>
> ---
> libavcodec/movtextdec.c | 109
> ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 106
> insertions(+), 3 deletions(-)
>
> diff --git a/libavcodec/movtextdec.c b/libavcodec/movtextdec.c
> index 869358c..451056c 100644
> --- a/libavcodec/movtextdec.c
> +++ b/libavcodec/movtextdec.c
> @@ -36,10 +36,17 @@
> #define HCLR_BOX (1<<2)
>
> typedef struct {
> + uint16_t fontID;
> + uint8_t font_name_length;
> + uint8_t font[20];
> +} FontRecord;
> +
> +typedef struct {
> uint16_t style_start;
> uint16_t style_end;
> uint8_t style_flag;
> uint8_t fontsize;
> + uint16_t style_fontID;
> } StyleBox;
>
> typedef struct {
> @@ -56,11 +63,13 @@ typedef struct {
> StyleBox *s_temp;
> HighlightBox h;
> HilightcolorBox c;
> + FontRecord **ftab;
> + FontRecord *ftab_temp;
> uint8_t box_flags;
> - uint16_t style_entries;
> + uint16_t style_entries, ftab_entries;
> uint64_t tracksize;
> int size_var;
> - int count_s;
> + int count_s, count_f;
> } MovTextContext;
>
> typedef struct {
> @@ -80,6 +89,80 @@ static void mov_text_cleanup(MovTextContext *m)
> }
> }
>
> +static void mov_text_cleanup_ftab(MovTextContext *m)
> +{
> + int i;
> + for(i = 0; i < m->count_f; i++) {
> + av_freep(&m->ftab[i]);
> + }
> + av_freep(&m->ftab);
> +}
> +
> +static int mov_text_t3xg(AVCodecContext *avctx, MovTextContext *m)
I'm pretty sure it's "tx3g"
> +{
> + char *t3xg_ptr = avctx->extradata;
> + int i, tracksize;
> +
> + tracksize = 38; /* Size till ftab_entries */
I'd say box size. It's not technically a track.
And make the 38 a constant.
> + if (avctx->extradata_size < tracksize)
> + return -1;
> +
> + m->ftab_entries = 0;
> + // Display Flags
> + t3xg_ptr += 4;
> + // Alignment
> + t3xg_ptr += 2;
> + // Background Color
> + t3xg_ptr += 4;
> + // BoxRecord
> + t3xg_ptr += 8;
> + // StyleRecord
> + t3xg_ptr += 12;
> + // FontRecord
> + // FontRecord Size
> + t3xg_ptr += 4;
> + // ftab
> + t3xg_ptr += 4;
> +
> + tracksize += 2;
> + if (avctx->extradata_size < tracksize)
> + return -1;
Why not just initialize tracksize to 40? The extra += 2 isn't optional.
> +
> + m->ftab_entries = AV_RB16(t3xg_ptr);
> + t3xg_ptr += 2;
> +
> + for (i = 0; i < m->ftab_entries; i++) {
> +
> + tracksize += 3;
> + if (avctx->extradata_size < tracksize) {
> + m->ftab_entries = 0;
> + return -1;
> + }
You need to clean up any ftab entries that have already been processed.
> + m->ftab_temp = av_malloc(sizeof(*m->ftab_temp));
> + if (!m->ftab_temp) {
> + mov_text_cleanup_ftab(m);
> + return AVERROR(ENOMEM);
> + }
> + m->ftab_temp->fontID = AV_RB16(t3xg_ptr);
> + t3xg_ptr += 2;
> + m->ftab_temp->font_name_length = *t3xg_ptr++;
> +
> + tracksize = tracksize + m->ftab_temp->font_name_length;
> + if ((avctx->extradata_size < tracksize) ||
> (m->ftab_temp->font_name_length > 20)) {
> + m->ftab_entries = 0;
> + return -1;
> + }
> + memcpy(m->ftab_temp->font, t3xg_ptr,
> m->ftab_temp->font_name_length);
> + av_dynarray_add(&m->ftab, &m->count_f, m->ftab_temp);
> + if (!m->ftab) {
> + mov_text_cleanup_ftab(m);
> + return AVERROR(ENOMEM);
> + }
I didn't think about this before, but there's no need to store the font
name and length in your FontRecord in this way. Just store it as a
normal null terminated string. Then you don't need the size and do can
do normal string manipulation on it later (like using av_bprintf with
'%s').
> + t3xg_ptr = t3xg_ptr + 3 + m->ftab[i]->font_name_length;
> + }
> + return 0;
> +}
> +
> static int decode_hlit(const uint8_t *tsmb, MovTextContext *m,
> AVPacket *avpkt) {
> m->box_flags |= HLIT_BOX;
> @@ -118,7 +201,7 @@ static int decode_styl(const uint8_t *tsmb,
> MovTextContext *m, AVPacket *avpkt) tsmb += 2;
> m->s_temp->style_end = AV_RB16(tsmb);
> tsmb += 2;
> - // fontID = AV_RB16(tsmb);
> + m->s_temp->style_fontID = AV_RB16(tsmb);
> tsmb += 2;
> m->s_temp->style_flag = AV_RB8(tsmb);
> tsmb++;
> @@ -147,6 +230,7 @@ static int text_to_ass(AVBPrint *buf, const char
> *text, const char *text_end, MovTextContext *m)
> {
> int i = 0;
> + int j = 0;
> int text_pos = 0;
> while (text < text_end) {
> if (m->box_flags & STYL_BOX) {
> @@ -164,6 +248,14 @@ static int text_to_ass(AVBPrint *buf, const char
> *text, const char *text_end, if (m->s[i]->style_flag &
> STYLE_FLAG_UNDERLINE) av_bprintf(buf, "{\\u1}");
> av_bprintf(buf, "{\\fs%d}", m->s[i]->fontsize);
> + av_bprintf(buf, "{\\fn");
> + for (j = 0; j < m->ftab_entries; j++) {
> + if (m->s[i]->style_fontID ==
> m->ftab[j]->fontID) {
> + av_bprint_append_data(buf,
> m->ftab[j]->font,
> +
> m->ftab[j]->font_name_length);
> + }
> + }
> + av_bprintf(buf, "}");
> }
> }
> }
> @@ -215,6 +307,8 @@ static int mov_text_init(AVCodecContext *avctx) {
> * it's very common to find files where the default style is
> broken
> * and respecting it results in a worse experience than ignoring
> it. */
> + MovTextContext *m = avctx->priv_data;
> + mov_text_t3xg(avctx, m);
> return ff_ass_subtitle_header_default(avctx);
> }
>
> @@ -265,6 +359,7 @@ static int mov_text_decode_frame(AVCodecContext
> *avctx, m->style_entries = 0;
> m->box_flags = 0;
> m->count_s = 0;
> + m->count_f = 0;
> // Note that the spec recommends lines be no longer than 2048
> characters. av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
> if (text_length + 2 != avpkt->size) {
> @@ -313,6 +408,13 @@ static int mov_text_decode_frame(AVCodecContext
> *avctx, return avpkt->size;
> }
>
> +static int mov_text_decode_close(AVCodecContext *avctx)
> +{
> + MovTextContext *m = avctx->priv_data;
> + mov_text_cleanup_ftab(m);
> + return 0;
> +}
> +
> AVCodec ff_movtext_decoder = {
> .name = "mov_text",
> .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"),
> @@ -321,4 +423,5 @@ AVCodec ff_movtext_decoder = {
> .priv_data_size = sizeof(MovTextContext),
> .init = mov_text_init,
> .decode = mov_text_decode_frame,
> + .close = mov_text_decode_close,
> };
--phil
More information about the ffmpeg-devel
mailing list