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 15A0D4843E for ; Mon, 4 Dec 2023 07:52:15 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 0EA3E68CED5; Mon, 4 Dec 2023 09:52:14 +0200 (EET) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 3E48368B416 for ; Mon, 4 Dec 2023 09:52:07 +0200 (EET) Received: from tutadb.w10.tutanota.de (unknown [192.168.1.10]) by w4.tutanota.de (Postfix) with ESMTP id EAE8910602EC for ; Mon, 4 Dec 2023 07:52:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1701676326; s=s1; d=lynne.ee; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding:Cc:Date:Date:In-Reply-To:In-Reply-To:MIME-Version:MIME-Version:Message-ID:Message-ID:Reply-To:References:References:Sender; bh=WSVK9Zy577tdBOWTVZQkI3T/F8z7sltaHiDBC19Wxco=; b=wOZlr0M6VdrCNGKCyATCbHNz5M0B/kPji1Vau52+B64piUq3XkvA1OyxAmKjNlVR ST3E5yT3TjD5ruoeTWHM5rphH0l9BSy6tRg3E2Av4SiP5hyRGXHqRg4VYE7haZaH79l WipSgtvusQy7hfrInB+RmxGys9chXQ/lKnhVovW5j6E3urSHa4puuZ48zJUDvTq+euA JyJCixhKRMLNSrCAIs+ywZZcWAK+i0DB2VAf4R9/8QegyTuxckVO0UeotPaF4x8RT5a 8OjPGDaPphUUdjTS4IO95vp6QdH7kBRRk8R39Sep4lsg1XLo6831nhZPlk9wVRctFBv qdO55nUzdQ== Date: Mon, 4 Dec 2023 08:52:06 +0100 (CET) From: Lynne To: FFmpeg development discussions and patches Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_133439_1191317064.1701676326956" Subject: [FFmpeg-devel] [PATCH 2/2] aacdec: fix single-sample delay for SBR streams 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 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: ------=_Part_133439_1191317064.1701676326956 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Our SBR implementation introduces a single sample of latency into the output, which is currently never skipped. This delay is separate from any container skip value and always present, as it is from an additional part of the decoding process. Fixes Trac issue #9667 ------=_Part_133439_1191317064.1701676326956 Content-Type: text/x-diff; charset=us-ascii; name=0002-aacdec-fix-single-sample-delay-for-SBR-streams.patch Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=0002-aacdec-fix-single-sample-delay-for-SBR-streams.patch >From 5b9d971b108677d54bc3aac317669007462dbcc9 Mon Sep 17 00:00:00 2001 From: Lynne Date: Mon, 30 Oct 2023 05:40:22 +0100 Subject: [PATCH 2/2] aacdec: fix single-sample delay for SBR streams Our SBR implementation introduces a single sample of latency into the output, which is currently never skipped. This delay is separate from any container skip value and always present, as it is from an additional part of the decoding process. Fixes Trac issue #9667 --- libavcodec/aac.h | 1 + libavcodec/aacdec_template.c | 23 ++++++++++++++++++----- 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/libavcodec/aac.h b/libavcodec/aac.h index 285d3b7482..06ae2222cf 100644 --- a/libavcodec/aac.h +++ b/libavcodec/aac.h @@ -298,6 +298,7 @@ struct AACContext { AVCodecContext *avctx; AVFrame *frame; + int skip_samples; int is_saved; ///< Set if elements have stored overlap from previous frame. DynamicRangeControl che_drc; diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c index 2b3509c85f..a82cd69a60 100644 --- a/libavcodec/aacdec_template.c +++ b/libavcodec/aacdec_template.c @@ -529,6 +529,8 @@ static void flush(AVCodecContext *avctx) } } } + + ac->skip_samples = 1; } /** @@ -1222,6 +1224,7 @@ static av_cold int aac_decode_init(AVCodecContext *avctx) return AVERROR(ENOMEM); } + ac->skip_samples = 1; ac->random_state = 0x1f2e3d4c; #define MDCT_INIT(s, fn, len, sval) \ @@ -2390,7 +2393,7 @@ static int decode_dynamic_range(DynamicRangeControl *che_drc, static int decode_fill(AACContext *ac, GetBitContext *gb, int len) { uint8_t buf[256]; - int i, major, minor; + int i; if (len < 13+7*8) goto unknown; @@ -2404,10 +2407,6 @@ static int decode_fill(AACContext *ac, GetBitContext *gb, int len) { if (ac->avctx->debug & FF_DEBUG_PICT_INFO) av_log(ac->avctx, AV_LOG_DEBUG, "FILL:%s\n", buf); - if (sscanf(buf, "libfaac %d.%d", &major, &minor) == 2){ - ac->avctx->internal->skip_samples = 1024; - } - unknown: skip_bits_long(gb, len); @@ -3374,6 +3373,20 @@ static int aac_decode_frame(AVCodecContext *avctx, AVFrame *frame, if (buf[buf_offset]) break; + if (ac->skip_samples) { + int skip = 0; + + /* Our SBR implementation introduces a sample of delay into the output. */ + if (ac->oc[1].m4ac.sbr) + skip = 1; + + err = ff_decode_skip_samples(avctx, frame, skip); + if (err < 0) + return err; + + ac->skip_samples = 0; + } + return buf_size > buf_offset ? buf_consumed : buf_size; } -- 2.43.0 ------=_Part_133439_1191317064.1701676326956 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ 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". ------=_Part_133439_1191317064.1701676326956--