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 EEA7345D8F for ; Tue, 9 May 2023 15:48:06 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id AD23068C235; Tue, 9 May 2023 18:48:03 +0300 (EEST) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 3A38A68BF82 for ; Tue, 9 May 2023 18:47:57 +0300 (EEST) Received: from tutadb.w10.tutanota.de (unknown [192.168.1.10]) by w4.tutanota.de (Postfix) with ESMTP id 1BC7910602E4 for ; Tue, 9 May 2023 15:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1683647275; s=s1; d=lynne.ee; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding: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=AH1eX72WTpPP+knnia3uZBFnolb1WuWSwc9hTpsUlVY=; b=3mZ+BpFCVsX6yfXR+B43iwhxZ7NcQlc/ZfCGr9q2bFb4k8Bg+r0FTbQu2yb5yXjA YQbTmjM7YNkXlW8S2tBvGN7ZvY1eIrsovyPD4Jld7NBGLU/4fQG33LxdKLIZclsocpJ cjnX3ru93RM0vovl28IgmA4iUsdwbCaYA8TyoExFVs7xLb3x9T7bqH7FHW8XoB0zTDO 0D8TEjzR1ycHpWgozkL8aITgtxPl8a2Edo736lAjuFq444r8ZThLazEtFQoW3xAYypi UwSr3OIIuTz3LpNUOSjm5YkDLmTicfWJ3F/XoY2NIwMfuotAUmSKuyoO6MlwLYL6svD 8iUcTeTkKA== Date: Tue, 9 May 2023 17:47:55 +0200 (CEST) From: Lynne To: FFmpeg development discussions and patches Message-ID: In-Reply-To: <20230509095030.25506-1-arnie.chang@sifive.com> References: <20230509095030.25506-1-arnie.chang@sifive.com> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH 0/5] RISC-V: Improve H264 decoding performance using RVV intrinsic 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: May 9, 2023, 11:51 by arnie.chang@sifive.com: > We are submitting a set of patches that significantly improve H.264 decoding performance > by utilizing RVV intrinsic code. The average speedup(FPS) achieved by these patches is more than 2x, > as experimented on 720P videos running on an internal FPGA board. > > Patch1: add support for RVV intrinsic code in the configure file > Patch2: optimize chroma motion compensation > Patch3: optimize luma motion compensation > Patch4: optimize dsp functions, such as IDCT, in-loop filtering, and weighed filtering > Patch5: optimize intra prediction > > Arnie Chang (5): > configure: Add detection of RISC-V vector intrinsic support > lavc/h264chroma: Add vectorized implementation of chroma MC for RISC-V > lavc/h264qpel: Add vectorized implementation of luma MC for RISC-V > lavc/h264dsp: Add vectorized implementation of DSP functions for > RISC-V > lavc/h264pred: Add vectorized implementation of intra prediction for > RISC-V > Could you rewrite this in asm instead? I'd like for risc-v to have the same policy like we do for arm - no intrinsics. There's a long list of reasons we don't use intrinsics which I won't get into. Just a few days ago, I discovered that our PPC intrinsics were quite badly performing due to compiler issues, in some cases, 500x slower than C. Also, we don't care about overall speedup. We have checkasm --bench to measure the per-function speedup over C. _______________________________________________ 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".