From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 3C25D487C7 for ; Mon, 18 Dec 2023 04:02:08 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 531EB68D174; Mon, 18 Dec 2023 06:02:05 +0200 (EET) Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 21E2368CFD0 for ; Mon, 18 Dec 2023 06:01:57 +0200 (EET) Received: from smtp202.mailbox.org (smtp202.mailbox.org [10.196.197.202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4StmNf079nz9sX2 for ; Mon, 18 Dec 2023 05:01:54 +0100 (CET) Message-ID: Date: Mon, 18 Dec 2023 09:31:52 +0530 MIME-Version: 1.0 To: ffmpeg-devel@ffmpeg.org References: <20231216101414.12607-1-ffmpeg@gyani.pro> Content-Language: en-US From: Gyan Doshi In-Reply-To: <20231216101414.12607-1-ffmpeg@gyani.pro> Subject: Re: [FFmpeg-devel] [PATCH v3] swr/swresample: avoid reapplication of firstpts X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On 2023-12-16 03:44 pm, Gyan Doshi wrote: > During a resampling operation where > > 1) user has specified first_pts > 2) SWR_FLAG_RESAMPLE is not set initially (directly or otherwise) > 3) first_pts has been fulfilled (always using hard compensation) > > then upon first encountering a delay where a soft compensation is > required, swr_set_compensation will lead to another init of swr which > will reset outpts to the specified firstpts thus leading to an output > frame having its pts = firstpts. When the next input frame is received, > swr will see a large delay and inject silence from firstpts to the > current frame's pts. This can lead to severe desync and in worst case, > loss of audio playback. > > Parameter firstpts initialized to AV_NOPTS_VALUE in swr_alloc and then > checked in swr_init to avoid resetting outpts, thus avoiding reapplication > of firstpts. > > Fixes #4131. > --- > Added fate test Plan to push soon. Regards, Gyan > > libswresample/options.c | 1 + > libswresample/swresample.c | 5 +++-- > tests/fate/libswresample.mak | 3 +++ > tests/ref/fate/swr-async-firstpts | 24 ++++++++++++++++++++++++ > 4 files changed, 31 insertions(+), 2 deletions(-) > create mode 100644 tests/ref/fate/swr-async-firstpts > > diff --git a/libswresample/options.c b/libswresample/options.c > index fb109fdbab..d8cf85c053 100644 > --- a/libswresample/options.c > +++ b/libswresample/options.c > @@ -171,6 +171,7 @@ av_cold struct SwrContext *swr_alloc(void){ > if(s){ > s->av_class= &av_class; > av_opt_set_defaults(s); > + s->firstpts = AV_NOPTS_VALUE; > } > return s; > } > diff --git a/libswresample/swresample.c b/libswresample/swresample.c > index f2a9b40474..1cf83a803f 100644 > --- a/libswresample/swresample.c > +++ b/libswresample/swresample.c > @@ -375,8 +375,9 @@ av_cold int swr_init(struct SwrContext *s){ > if (s->firstpts_in_samples != AV_NOPTS_VALUE) { > if (!s->async && s->min_compensation >= FLT_MAX/2) > s->async = 1; > - s->firstpts = > - s->outpts = s->firstpts_in_samples * s->out_sample_rate; > + if (s->firstpts == AV_NOPTS_VALUE) > + s->firstpts = > + s->outpts = s->firstpts_in_samples * s->out_sample_rate; > } else > s->firstpts = AV_NOPTS_VALUE; > > diff --git a/tests/fate/libswresample.mak b/tests/fate/libswresample.mak > index f2108016af..0d29f76024 100644 > --- a/tests/fate/libswresample.mak > +++ b/tests/fate/libswresample.mak > @@ -1082,6 +1082,9 @@ $(call CROSS_TEST,$(SAMPLERATES_LITE),ARESAMPLE_EXACT_LIN_ASYNC,s32p,s32le,s16) > $(call CROSS_TEST,$(SAMPLERATES_LITE),ARESAMPLE_EXACT_LIN_ASYNC,fltp,f32le,s16) > $(call CROSS_TEST,$(SAMPLERATES_LITE),ARESAMPLE_EXACT_LIN_ASYNC,dblp,f64le,s16) > > +FATE_SWR_RESAMPLE-$(call FILTERDEMDEC, ARESAMPLE ASETPTS ATRIM SINE, , PCM_S16LE, LAVFI_INDEV) += fate-swr-async-firstpts > +fate-swr-async-firstpts: CMD = framecrc -auto_conversion_filters -copyts -f lavfi -i "sine=r=1000:samples_per_frame=100,asetpts=PTS+S+S*floor(ld(1)/4)+st(1\,ld(1)+1)*0,atrim=end=2" -filter:a aresample=async=300:first_pts=0 > + > FATE_SWR_RESAMPLE-$(call FILTERDEMDECENCMUX, ARESAMPLE, WAV, PCM_S16LE, PCM_S16LE, WAV) += $(FATE_SWR_RESAMPLE) > fate-swr-resample: $(FATE_SWR_RESAMPLE-yes) > FATE_SWR += $(FATE_SWR_RESAMPLE-yes) > diff --git a/tests/ref/fate/swr-async-firstpts b/tests/ref/fate/swr-async-firstpts > new file mode 100644 > index 0000000000..3f6b290bab > --- /dev/null > +++ b/tests/ref/fate/swr-async-firstpts > @@ -0,0 +1,24 @@ > +#tb 0: 1/1000 > +#media_type 0: audio > +#codec_id 0: pcm_s16le > +#sample_rate 0: 1000 > +#channel_layout_name 0: mono > +0, 0, 0, 132, 264, 0xc2981f45 > +0, 132, 132, 68, 136, 0xe78e468d > +0, 200, 200, 100, 200, 0xd55c67d0 > +0, 300, 300, 100, 200, 0xd55c67d0 > +0, 400, 400, 100, 200, 0xd55c67d0 > +0, 500, 500, 93, 186, 0x85ca5db4 > +0, 593, 593, 110, 220, 0xa2655d0b > +0, 703, 703, 108, 216, 0x95cb6f01 > +0, 811, 811, 108, 216, 0xf35668b8 > +0, 919, 919, 149, 298, 0xc273245f > +0, 1068, 1068, 136, 272, 0xedeb6e0a > +0, 1204, 1204, 98, 196, 0xea18668e > +0, 1302, 1302, 98, 196, 0x412861e7 > +0, 1400, 1400, 98, 196, 0x7ec361b2 > +0, 1498, 1498, 110, 220, 0xf3ae6a6a > +0, 1608, 1608, 108, 216, 0xab2f6c93 > +0, 1716, 1716, 107, 214, 0x50de6eb9 > +0, 1823, 1823, 106, 212, 0x67b8656d > +0, 1929, 1929, 18, 36, 0x2b7911c6 _______________________________________________ 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".