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

Niklesh Lalwani lalwani1994 at gmail.com
Fri Aug 7 17:06:09 CEST 2015


The leak was happening because the m->count_f was initialised to 0 at the
wrong place which was used in freeing the mem allocs. I am posting a patch
to fix that.

Thanks,
Niklesh

On Fri, Aug 7, 2015 at 5:11 AM, Michael Niedermayer <michael at niedermayer.cc>
wrote:

> 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
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>


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