Message ID | 20240328091134.388-1-tong1.wu@intel.com |
---|---|
State | New |
Headers | show |
Series | [FFmpeg-devel] 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 Thu, Mar 28, 2024 at 10:12 AM <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> I've been looking into some playback glitches after 456c8ebe7c7dcd766d36cd0296815d89fd1166b5 and I can confirm that this patch fixes those as well. Using the fixed position of the *hdr member and its offset seems a bit icky though, and _at least_ could use a comment so future changes keep it last. - Hendrik
>From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of >Hendrik Leppkes >Sent: Thursday, March 28, 2024 5:43 PM >To: FFmpeg development discussions and patches <ffmpeg- >devel@ffmpeg.org> >Subject: Re: [FFmpeg-devel] [PATCH] avcodec/hevc_ps: fix the problem of >memcmp losing effectiveness > >On Thu, Mar 28, 2024 at 10:12 AM <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> > >I've been looking into some playback glitches after >456c8ebe7c7dcd766d36cd0296815d89fd1166b5 and I can confirm that this >patch fixes those as well. > >Using the fixed position of the *hdr member and its offset seems a bit >icky though, and _at least_ could use a comment so future changes keep >it last. Comment is added to the header. Thanks, Tong
diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c index cbef3ef4cd..8b3a27a17c 100644 --- a/libavcodec/hevc_ps.c +++ b/libavcodec/hevc_ps.c @@ -449,6 +449,16 @@ 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) || + (vps1->hdr && vps2->hdr && !memcmp(vps1->hdr, vps2->hdr, sizeof(*vps1->hdr)))) { + return !memcmp(vps1, vps2, offsetof(HEVCVPS, hdr)); + } + + return 0; +} + int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx, HEVCParamSets *ps) { @@ -545,9 +555,11 @@ 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 +581,7 @@ 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..8edac2508d 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 +174,7 @@ typedef struct HEVCVPS { uint8_t data[4096]; int data_size; + HEVCHdrParams *hdr; } HEVCVPS; typedef struct ScalingList {