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[79.124.17.100]) by mx.google.com with ESMTP id x13si9577077eds.134.2022.02.01.13.22.10; Tue, 01 Feb 2022 13:22:11 -0800 (PST) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@gmail.com header.s=20210112 header.b=nhTDsuIY; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org; dmarc=fail (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 056A368AD28; Tue, 1 Feb 2022 23:21:19 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from mail-qv1-f44.google.com (mail-qv1-f44.google.com [209.85.219.44]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 34D9868AFAB for ; Tue, 1 Feb 2022 23:21:11 +0200 (EET) Received: by mail-qv1-f44.google.com with SMTP id d8so17261397qvv.2 for ; Tue, 01 Feb 2022 13:21:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=X2N5XKzDYx58j9X2eT8mygoUZncUAn6a6PB0VDV2pgQ=; b=nhTDsuIYWex+8zHDljc7yI0NenVojq5nRftWET/jTRSZ0PGhKTlqXGA3r3Da8NnV34 C8ShBodgS0K+RXzoQjafU9sKBiSkYMES1pGhCcbgDKE6J0Y3FQ66VkV2mYofSZj9Uqc6 X5D9pCXEKkXtmjQzO2yyDrFj2Xcc8TFvz86uM02mN8Sw8K31G/OGEHbREf9H4kGZtJg9 14ozILJ3P+0gcxweCeMBS3oRRzHp7QtddzpVQmCK7UnBAVAcsHVkOtU71at9UbHHRPj0 zH2vmFHksv6pRbbf9sYbP/KjsQ9fSWqtLPjL8wuCviKzIu/Mq+TqMqRuZzsYmPjcVs8T x1Lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=X2N5XKzDYx58j9X2eT8mygoUZncUAn6a6PB0VDV2pgQ=; b=l0labO91QHF1wmqB8u836ZA4KEX7V4OFqzVTtu8AOJmqCX6OMhy7z4t/xt/y+1JqEd 98NOQWz825tHPPNYFKl0agm6pgUMqzb6KKJfafkHuP/EE60x4kywGJ5ZXfkDgf9IdQwR vwQLwDKBGFutd7HGeNxcmugZya2L/gYbYeIVBpnTy6Cl2/zzn2yok94qz2jYI9vILv5+ GLHZzJQuHcEEGY/tM8nyLdfq7yhu/iIEXf60ketfjHN1ui/icDOZ5De3gHdlmN14FyUS GfulUOTa3UVnDoc9iwxgBjGVKYZQkuctl3tRiri/ICgCNZ2OdOh+wfbD7cT4feF6u0lH 9agw== X-Gm-Message-State: AOAM533s7WQkqxbMumOBGQW9ooHjoSYjI3wFtk2IGTG9jXfKj9XMrBPO 9oZq9zzkeTlv9HGwAg8AU6vocFYUpRz9Tg== X-Received: by 2002:a05:6214:1bcc:: with SMTP id m12mr24418935qvc.76.1643750469833; Tue, 01 Feb 2022 13:21:09 -0800 (PST) Received: from localhost.localdomain ([151.200.235.219]) by smtp.gmail.com with ESMTPSA id ay18sm2928225qkb.8.2022.02.01.13.21.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Feb 2022 13:21:09 -0800 (PST) From: Scott Theisen To: ffmpeg-devel@ffmpeg.org Date: Tue, 1 Feb 2022 16:20:53 -0500 Message-Id: <20220201212056.29712-6-scott.the.elm@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220201212056.29712-1-scott.the.elm@gmail.com> References: <20220201212056.29712-1-scott.the.elm@gmail.com> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH 5/8] avpriv_find_start_code(): replace unnecessary for loop 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 Cc: Scott Theisen Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: H+CFaNs1QTcu start_code will still be invalid, i.e. all ones, but will no longer have up to the first three bytes in p shifted in. --- libavcodec/utils.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/libavcodec/utils.c b/libavcodec/utils.c index 54c9dd056d..b4c5fa5009 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -944,19 +944,14 @@ const uint8_t *avpriv_find_start_code(const uint8_t *av_restrict p, const uint8_t *end, uint32_t *av_restrict start_code) { - int i; + *start_code = ~0; av_assert0(p <= end); - if (p >= end) + // minimum length for a start code + if (p + 4 > end) return end; - *start_code = ~0; - for (i = 0; i < 3; i++) { - uint32_t tmp = *start_code << 8; - *start_code = tmp + *(p++); - if (tmp == 0x100 || p == end) - return p; - } + p += 3; // offset for negative indices in while loop /* with memory address increasing left to right, we are looking for (in hexadecimal): * 00 00 01 XX