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 8252446CE0 for ; Thu, 7 Sep 2023 19:27:59 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 0A8D568C890; Thu, 7 Sep 2023 22:27:40 +0300 (EEST) Received: from smtp6-g21.free.fr (smtp6-g21.free.fr [212.27.42.6]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id B6AC868C884 for ; Thu, 7 Sep 2023 22:27:33 +0300 (EEST) Received: from localhost.localdomain (unknown [IPv6:2a01:e0a:8a7:6440:a506:2525:387f:fe6d]) (Authenticated sender: christophe.gisquet@free.fr) by smtp6-g21.free.fr (Postfix) with ESMTPSA id 583E2780375 for ; Thu, 7 Sep 2023 21:27:32 +0200 (CEST) From: Christophe Gisquet To: ffmpeg-devel@ffmpeg.org Date: Thu, 7 Sep 2023 21:27:21 +0200 Message-ID: <20230907192721.50459-3-christophe.gisquet@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230907192721.50459-1-christophe.gisquet@gmail.com> References: <20230907192721.50459-1-christophe.gisquet@gmail.com> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH 2/2] read_xbits: request fewer bits 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: This would have also helped a bitstream reader with a cache of 32 bits. --- libavcodec/bitstream_template.h | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/libavcodec/bitstream_template.h b/libavcodec/bitstream_template.h index 3f90fc6a07..c27e8108b2 100644 --- a/libavcodec/bitstream_template.h +++ b/libavcodec/bitstream_template.h @@ -423,8 +423,18 @@ static inline const uint8_t *BS_FUNC(align)(BSCTX *bc) */ static inline int BS_FUNC(read_xbits)(BSCTX *bc, unsigned int n) { - int32_t cache = BS_FUNC(peek)(bc, 32); - int sign = ~cache >> 31; + int32_t cache; + int sign; + + if (n > bc->bits_valid) + BS_FUNC(priv_refill_32)(bc); + +#if defined(BITSTREAM_READER_LE) + cache = bc->bits & 0xFFFFFFFF; +#else + cache = bc->bits >> 32; +#endif + sign = ~cache >> 31; BS_FUNC(skip_remaining)(bc, n); return ((((uint32_t)(sign ^ cache)) >> (32 - n)) ^ sign) - sign; -- 2.42.0 _______________________________________________ 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".