Message ID | 20240329151307.659-1-tong1.wu@intel.com |
---|---|
State | New |
Headers | show |
Series | [FFmpeg-devel,v2] avcodec/hevc_ps: fix the problem of memcmp losing effectiveness | expand |
Context | Check | Description |
---|---|---|
yinshiyou/make_loongarch64 | success | Make finished |
yinshiyou/make_fate_loongarch64 | success | Make fate finished |
andriy/make_x86 | success | Make finished |
andriy/make_fate_x86 | success | Make fate finished |
On 3/29/2024 12:13 PM, tong1.wu-at-intel.com@ffmpeg.org wrote: > From: Tong Wu <tong1.wu@intel.com> > > HEVCHdrParams* receives a pointer which points to a dynamically > allocated memory block. It causes the memcmp always returning 1. > Add a function to do the comparision. A condition is also added to > avoid malloc(0). > > Signed-off-by: Tong Wu <tong1.wu@intel.com> > --- > libavcodec/hevc_ps.c | 22 ++++++++++++++++++---- > libavcodec/hevc_ps.h | 4 +++- > 2 files changed, 21 insertions(+), 5 deletions(-) > > diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c > index cbef3ef4cd..d3c589ec24 100644 > --- a/libavcodec/hevc_ps.c > +++ b/libavcodec/hevc_ps.c > @@ -449,6 +449,18 @@ static void uninit_vps(FFRefStructOpaque opaque, void *obj) > av_freep(&vps->hdr); > } > > +static int compare_vps(const HEVCVPS *vps1, const HEVCVPS *vps2) > +{ > + if (!vps1->hdr && !vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, hdr))) > + return 1; > + > + if (vps1->hdr && vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, hdr)) && > + !memcmp(vps1->hdr, vps2->hdr, vps1->vps_num_hrd_parameters * sizeof(*vps1->hdr))) > + return 1; > + > + return 0; > +} Something like this should be simpler > +static int compare_vps(const HEVCVPS *vps1, const HEVCVPS *vps2) > +{ > + if (!memcmp(vps1, vps2, offsetof(HEVCVPS, hdr))) > + return !vps1->vps_num_hrd_parameters || > + !memcmp(vps1->hdr, vps2->hdr, vps1->vps_num_hrd_parameters * sizeof(*vps1->hdr)); > + > + return 0; > +} If vps1 is equal to vps2 up to hdr, then vps_num_hrd_parameters will be the same in both and you can safely just go ahead with the memcmp for hdr.
>From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of James >Almer >Sent: Friday, March 29, 2024 11:18 PM >To: ffmpeg-devel@ffmpeg.org >Subject: Re: [FFmpeg-devel] [PATCH v2] avcodec/hevc_ps: fix the problem of >memcmp losing effectiveness > >On 3/29/2024 12:13 PM, tong1.wu-at-intel.com@ffmpeg.org wrote: >> From: Tong Wu <tong1.wu@intel.com> >> >> HEVCHdrParams* receives a pointer which points to a dynamically >> allocated memory block. It causes the memcmp always returning 1. >> Add a function to do the comparision. A condition is also added to >> avoid malloc(0). >> >> Signed-off-by: Tong Wu <tong1.wu@intel.com> >> --- >> libavcodec/hevc_ps.c | 22 ++++++++++++++++++---- >> libavcodec/hevc_ps.h | 4 +++- >> 2 files changed, 21 insertions(+), 5 deletions(-) >> >> diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c >> index cbef3ef4cd..d3c589ec24 100644 >> --- a/libavcodec/hevc_ps.c >> +++ b/libavcodec/hevc_ps.c >> @@ -449,6 +449,18 @@ static void uninit_vps(FFRefStructOpaque opaque, >void *obj) >> av_freep(&vps->hdr); >> } >> >> +static int compare_vps(const HEVCVPS *vps1, const HEVCVPS *vps2) >> +{ >> + if (!vps1->hdr && !vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, >hdr))) >> + return 1; >> + >> + if (vps1->hdr && vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, >hdr)) && >> + !memcmp(vps1->hdr, vps2->hdr, vps1->vps_num_hrd_parameters * >sizeof(*vps1->hdr))) >> + return 1; >> + >> + return 0; >> +} > >Something like this should be simpler > >> +static int compare_vps(const HEVCVPS *vps1, const HEVCVPS *vps2) >> +{ >> + if (!memcmp(vps1, vps2, offsetof(HEVCVPS, hdr))) >> + return !vps1->vps_num_hrd_parameters || >> + !memcmp(vps1->hdr, vps2->hdr, vps1->vps_num_hrd_parameters * >sizeof(*vps1->hdr)); >> + >> + return 0; >> +} > >If vps1 is equal to vps2 up to hdr, then vps_num_hrd_parameters will be >the same in both and you can safely just go ahead with the memcmp for hdr. That makes sense. Thank you. >_______________________________________________ >ffmpeg-devel mailing list >ffmpeg-devel@ffmpeg.org >https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > >To unsubscribe, visit link above, or email >ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c index cbef3ef4cd..d3c589ec24 100644 --- a/libavcodec/hevc_ps.c +++ b/libavcodec/hevc_ps.c @@ -449,6 +449,18 @@ static void uninit_vps(FFRefStructOpaque opaque, void *obj) av_freep(&vps->hdr); } +static int compare_vps(const HEVCVPS *vps1, const HEVCVPS *vps2) +{ + if (!vps1->hdr && !vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, hdr))) + return 1; + + if (vps1->hdr && vps2->hdr && !memcmp(vps1, vps2, offsetof(HEVCVPS, hdr)) && + !memcmp(vps1->hdr, vps2->hdr, vps1->vps_num_hrd_parameters * sizeof(*vps1->hdr))) + return 1; + + return 0; +} + int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx, HEVCParamSets *ps) { @@ -545,9 +557,11 @@ int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx, goto err; } - vps->hdr = av_calloc(vps->vps_num_hrd_parameters, sizeof(*vps->hdr)); - if (!vps->hdr) - goto err; + if (vps->vps_num_hrd_parameters) { + vps->hdr = av_calloc(vps->vps_num_hrd_parameters, sizeof(*vps->hdr)); + if (!vps->hdr) + goto err; + } for (i = 0; i < vps->vps_num_hrd_parameters; i++) { int common_inf_present = 1; @@ -569,7 +583,7 @@ int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx, } if (ps->vps_list[vps_id] && - !memcmp(ps->vps_list[vps_id], vps, sizeof(*vps))) { + compare_vps(ps->vps_list[vps_id], vps)) { ff_refstruct_unref(&vps); } else { remove_vps(ps, vps_id); diff --git a/libavcodec/hevc_ps.h b/libavcodec/hevc_ps.h index cc75aeb8d3..0d8eaf2b3e 100644 --- a/libavcodec/hevc_ps.h +++ b/libavcodec/hevc_ps.h @@ -153,7 +153,6 @@ typedef struct PTL { typedef struct HEVCVPS { unsigned int vps_id; - HEVCHdrParams *hdr; uint8_t vps_temporal_id_nesting_flag; int vps_max_layers; @@ -175,6 +174,9 @@ typedef struct HEVCVPS { uint8_t data[4096]; int data_size; + /* Put this at the end of the structure to make it easier to calculate the + * size before this pointer, which is used for memcmp */ + HEVCHdrParams *hdr; } HEVCVPS; typedef struct ScalingList {