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 C6B5747E8D for ; Mon, 30 Oct 2023 05:10:30 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id B1A3468CCB0; Mon, 30 Oct 2023 07:10:27 +0200 (EET) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id D543C68CBAB for ; Mon, 30 Oct 2023 07:10:21 +0200 (EET) Received: from tutadb.w10.tutanota.de (unknown [192.168.1.10]) by w4.tutanota.de (Postfix) with ESMTP id 8C1AC1060136 for ; Mon, 30 Oct 2023 05:10:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1698642621; 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=e/KqR42nebwWkGHIpAhpQcIQUoq86r89vlWsGdr9h90=; b=jbgER6ZiI+TnSQuCrjR4nu3TlwmGiVCG8O8Jjux4farDD2AmaXuQKreAenoIT+OW KMfJ8KA4eLVZVD5o2H4LXNveK/03rVBbQRE/RUcyNZiTOyeKKZjFNnSxLCesyz0cTTp jZNi2AIjjKl9M3QNFei/Oi2HJulR26tmYF1AtPlBShturqlZW9Qlh4MFiQACETLxJHK bQ+uvOL2MWTmK4BZ68c5yhGfVXgdhOEOL4T9Kjp8zFu51D0ukK1pxyrBLd+i1rJqRyA WjDmaAHJnA6rRPkQzti4LSofcIRUyz2FFGb/3JTW+4KjDKyAzXggIJmO2DLzKs+Ykqs 37UrKsSanA== Date: Mon, 30 Oct 2023 06:10:21 +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_190073_226557301.1698642621568" Subject: [FFmpeg-devel] [PATCH 2/2] aacdec: correctly skip padding at the start of frames and during seeking 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_190073_226557301.1698642621568 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Presently, our AAC decoder didn't skip any samples, unless the side data contained skip information. This uses the newly added ff_decoder_skip_samples function to skip samples on two levels: base, and additional. Base is the inherent decoder delay. Most containers already specify it, hence it is overwritten in that case. Additional is any extra samples that have to be skipped, in AAC's case, it's the delay introduced by SBR. Patch attached. ------=_Part_190073_226557301.1698642621568 Content-Type: text/x-diff; charset=us-ascii; name=0002-aacdec-correctly-skip-padding-at-the-start-of-frames.patch Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=0002-aacdec-correctly-skip-padding-at-the-start-of-frames.patch >From 82120460459cf90c330ff11fe0ccf4b954736b5c Mon Sep 17 00:00:00 2001 From: Lynne Date: Mon, 30 Oct 2023 05:40:22 +0100 Subject: [PATCH 2/2] aacdec: correctly skip padding at the start of frames and during seeking Presently, our AAC decoder didn't skip any samples, unless the side data contained skip information. This uses the newly added ff_decoder_skip_samples function to skip samples on two levels: base, and additional. Base is the inherent decoder delay. Most containers already specify it, hence it is overwritten in that case. Additional is any extra samples that have to be skipped, in AAC's case, it's the delay introduced by SBR. --- libavcodec/aac.h | 1 + libavcodec/aacdec_template.c | 24 +++++++++++++++++++----- 2 files changed, 20 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 954399f86b..ab3037c0d5 100644 --- a/libavcodec/aacdec_template.c +++ b/libavcodec/aacdec_template.c @@ -532,6 +532,8 @@ static void flush(AVCodecContext *avctx) } } } + + ac->skip_samples = 1; } /** @@ -1251,6 +1253,7 @@ 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) \ @@ -2419,7 +2422,7 @@ 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; @@ -2433,10 +2436,6 @@ 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); @@ -3403,6 +3402,21 @@ static int aac_decode_frame(AVCodecContext *avctx, AVFrame *frame, if (buf[buf_offset]) break; + if (ac->skip_samples) { + int additional = 0; + + if (ac->oc[1].m4ac.sbr) + additional = 3010; + + err = ff_decode_skip_samples(avctx, frame, + ac->oc[1].m4ac.frame_length_short ? 960 : 1024, + additional); + if (err < 0) + return err; + + ac->skip_samples = 0; + } + return buf_size > buf_offset ? buf_consumed : buf_size; } -- 2.42.0 ------=_Part_190073_226557301.1698642621568 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_190073_226557301.1698642621568--