[FFmpeg-devel] [PATCH] movtextdec.c: Add support for font names

Michael Niedermayer michael at niedermayer.cc
Fri Aug 7 01:41:26 CEST 2015


On Thu, Aug 06, 2015 at 09:17:17AM +0530, Niklesh Lalwani wrote:
> Changes incorporated.
> Updated patch attached.
> 
> Thanks,
> Niklesh
> 
> On Thu, Aug 6, 2015 at 7:51 AM, Philip Langdale <philipl at overt.org> wrote:
> 
> > On Thu, 6 Aug 2015 07:13:07 +0530
> > Niklesh Lalwani <lalwani1994 at gmail.com> wrote:
> >
> > > On Thu, Aug 6, 2015 at 2:02 AM, Philip Langdale <philipl at overt.org>
> > > wrote:
> > >
> > > > 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').
> > > >
> > >
> > > Yes, I can do that and add a null character at the end after memcopy,
> > > but I thought I'll define the structs as close as possible to the
> > > Records defined in 3GPP spec.
> > > Also, I think I should not limit the length to 20. Ideally, it is a
> > > uint8_t value. In that case, I'll need to malloc the size of font
> > > length.
> >
> > Oh my. I thought the 20 character limit was in the spec. If the spec
> > has no limit, then you can't have one either - you do need to malloc
> > and append a null. Thanks.
> >
> > >
> > > Rest all updated.
> > >
> > > Thanks,
> > > Niklesh
> > >
> > >
> > > > > +        t3xg_ptr = t3xg_ptr + 3 + m->ftab[i]->font_name_length;
> > > > > +    }
> > > >
> > > >
> >
> >
> >
> >
> > --phil
> >

>  movtextdec.c |  111 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 108 insertions(+), 3 deletions(-)
> 37db5db69384c01d089b330e06afe026dbedd132  0001-movtextdec.c-Add-support-for-font-names.patch
> From d0301d7fa75ee68d3234edb3be41728507093c72 Mon Sep 17 00:00:00 2001
> From: Niklesh <niklesh.lalwani at iitb.ac.in>
> Date: Thu, 6 Aug 2015 09:11:12 +0530
> Subject: [PATCH] movtextdec.c: Add support for font names
> 
> Signed-off-by: Niklesh <niklesh.lalwani at iitb.ac.in>
> ---
>  libavcodec/movtextdec.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 108 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/movtextdec.c b/libavcodec/movtextdec.c
> index 869358c..15dd434 100644
> --- a/libavcodec/movtextdec.c
> +++ b/libavcodec/movtextdec.c
> @@ -31,15 +31,23 @@
>  #define STYLE_FLAG_ITALIC       (1<<1)
>  #define STYLE_FLAG_UNDERLINE    (1<<2)
>  
> +#define BOX_SIZE_INITIAL    40
> +
>  #define STYL_BOX   (1<<0)
>  #define HLIT_BOX   (1<<1)
>  #define HCLR_BOX   (1<<2)
>  
>  typedef struct {
> +    uint16_t fontID;
> +    char *font;
> +} 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 +64,13 @@ 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 +90,85 @@ 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]->font);
> +        av_freep(&m->ftab[i]);
> +    }
> +    av_freep(&m->ftab);
> +}
> +
> +static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m)
> +{
> +    char *tx3g_ptr = avctx->extradata;
> +    int i, box_size, font_length;
> +
> +    m->ftab_entries = 0;
> +    box_size = BOX_SIZE_INITIAL; /* Size till ftab_entries */
> +    if (avctx->extradata_size < box_size)
> +        return -1;
> +
> +    // Display Flags
> +    tx3g_ptr += 4;
> +    // Alignment
> +    tx3g_ptr += 2;
> +    // Background Color
> +    tx3g_ptr += 4;
> +    // BoxRecord
> +    tx3g_ptr += 8;
> +    // StyleRecord
> +    tx3g_ptr += 12;
> +    // FontRecord
> +    // FontRecord Size
> +    tx3g_ptr += 4;
> +    // ftab
> +    tx3g_ptr += 4;
> +
> +    m->ftab_entries = AV_RB16(tx3g_ptr);
> +    tx3g_ptr += 2;
> +
> +    for (i = 0; i < m->ftab_entries; i++) {
> +
> +        box_size += 3;
> +        if (avctx->extradata_size < box_size) {
> +            mov_text_cleanup_ftab(m);
> +            m->ftab_entries = 0;
> +            return -1;
> +        }
> +        m->ftab_temp = av_malloc(sizeof(*m->ftab_temp));

this leaks:
http://fate.ffmpeg.org/report.cgi?time=20150806220451&slot=x86_64-archlinux-gcc-valgrindundef

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

it is not once nor twice but times without number that the same ideas make
their appearance in the world. -- Aristotle
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