{"id":2227374,"url":"http://patchwork.ozlabs.org/api/patches/2227374/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260423-audio-v1-3-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260423-audio-v1-3-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>","list_archive_url":null,"date":"2026-04-23T13:55:23","name":"[3/3] audio: Use unsigned PCM bias","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"0cc9218c7c56b4c3a4aef1b09b79b8c378061400","submitter":{"id":90980,"url":"http://patchwork.ozlabs.org/api/people/90980/?format=json","name":"Akihiko Odaki","email":"odaki@rsg.ci.i.u-tokyo.ac.jp"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260423-audio-v1-3-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp/mbox/","series":[{"id":501200,"url":"http://patchwork.ozlabs.org/api/series/501200/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=501200","date":"2026-04-23T13:55:20","name":"audio: Fix unsigned PCM conversion edge cases","version":1,"mbox":"http://patchwork.ozlabs.org/series/501200/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2227374/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2227374/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=fail reason=\"key not found in DNS\" header.d=rsg.ci.i.u-tokyo.ac.jp\n header.i=@rsg.ci.i.u-tokyo.ac.jp header.a=rsa-sha256 header.s=rs20250326\n header.b=pq+a8bAK;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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Thu, 23 Apr 2026 09:55:48 -0400","from h205.csg.ci.i.u-tokyo.ac.jp (h205.csg.ci.i.u-tokyo.ac.jp\n [133.11.54.205]) (authenticated bits=0)\n by www3579.sakura.ne.jp (8.16.1/8.16.1) with ESMTPSA id 63NDtV0O080520\n (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);\n Thu, 23 Apr 2026 22:55:32 +0900 (JST)\n (envelope-from odaki@rsg.ci.i.u-tokyo.ac.jp)"],"DKIM-Signature":"a=rsa-sha256; bh=LUD9ZuzLWd1LWP0Ys4/Osg9bdyCbmhuDYF4cvOBc8QE=;\n c=relaxed/relaxed; d=rsg.ci.i.u-tokyo.ac.jp;\n h=From:Message-Id:To:Subject:Date;\n s=rs20250326; t=1776952532; v=1;\n b=pq+a8bAK82rf1L8dNOlY+konlInhbzmOmh9OIngw9P8/A/NGl8jKANTryNWNlrXv\n i7VRHyxujS+MCkoukwzfs7DAkG8+cBFLDIpSR7QsL09mAzXC0OQiDVpIzi9BOp0i\n srIeE8mAVMLyQJHVw0zkk/CNGk/cTAH1RTfM5w8/48Zr+niJnKxlAePOVaCtWGpS\n RyPQGb35vymwCF9rYyONtLaTxNeqJwktVDdRL1/0gdr486oWDmABsj2zXmtfLVmK\n zunU8ue1HXum5JX9XxK4aB9UQ2iftObrlY2i+RJfoczAC5hYPILeCUL4KgyaFoqX\n LgWIYwcykpyJyWFZost5cA==","From":"Akihiko Odaki ","Date":"Thu, 23 Apr 2026 22:55:23 +0900","Subject":"[PATCH 3/3] audio: Use unsigned PCM bias","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260423-audio-v1-3-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>","References":"<20260423-audio-v1-0-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>","In-Reply-To":"<20260423-audio-v1-0-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>","To":"qemu-devel@nongnu.org","Cc":"Gerd Hoffmann ,\n =?utf-8?q?Marc-Andr=C3=A9_Lureau?= ,\n Akihiko Odaki ","X-Mailer":"b4 0.16-dev-16047","Received-SPF":"pass client-ip=49.212.243.89;\n envelope-from=odaki@rsg.ci.i.u-tokyo.ac.jp; helo=www3579.sakura.ne.jp","X-Spam_score_int":"-16","X-Spam_score":"-1.7","X-Spam_bar":"-","X-Spam_report":"(-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1,\n DKIM_SIGNED=0.1, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=no autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"Clang warns for the uint32_t clip_ instantiations because HALF cannot be\nrepresented with mixeng_real:\n\n[1115/2559] Compiling C object libqemuaudio.a.p/audio_mixeng.c.o\nIn file included from ../../qemu/audio/mixeng.c:147:\n../../qemu/audio/mixeng_template.h:68:70: warning: implicit conversion from 'unsigned int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-const-int-float-conversion]\n 68 | return ENDIAN_CONVERT((IN_T)((v * ((mixeng_real)IN_MAX / 2.f)) + HALF));\n | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~\n../../qemu/audio/mixeng_template.h:31:22: note: expanded from macro 'HALF'\n 31 | #define HALF (IN_MAX >> 1)\n | ^\n../../qemu/audio/mixeng.c:146:28: note: expanded from macro 'ENDIAN_CONVERT'\n 146 | #define ENDIAN_CONVERT(v) (v)\n | ^\nIn file included from ../../qemu/audio/mixeng.c:152:\n../../qemu/audio/mixeng_template.h:68:70: warning: implicit conversion from 'unsigned int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-const-int-float-conversion]\n 68 | return ENDIAN_CONVERT((IN_T)((v * ((mixeng_real)IN_MAX / 2.f)) + HALF));\n | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~\n../../qemu/audio/mixeng_template.h:31:22: note: expanded from macro 'HALF'\n 31 | #define HALF (IN_MAX >> 1)\n | ^\n../../qemu/audio/mixeng.c:151:36: note: expanded from macro 'ENDIAN_CONVERT'\n 151 | #define ENDIAN_CONVERT(v) bswap32 (v)\n | ~~~~~~~~~^~\n/Users/person/v/qemu/include/qemu/bswap.h:10:39: note: expanded from macro 'bswap32'\n 10 | #define bswap32(_x) __builtin_bswap32(_x)\n | ^~\n2 warnings generated.\n\nHALF is not the right value here anyway. IN_MAX is odd, so the integer\nsample range has two middle codes. Unsigned PCM normally uses the upper\nmiddle code as the \"bias\": 0x80, 0x8000, or 0x80000000. HALF is instead\ndefined as the lower middle code: 0x7f, 0x7fff, or 0x7fffffff.\n\nReplace HALF with BIAS, defined as the upper middle code. This fixes the\nwarnings, since the value can be exactly represented with mixeng_real.\n\nSigned-off-by: Akihiko Odaki \n---\n audio/mixeng_template.h | 16 +++++++---------\n 1 file changed, 7 insertions(+), 9 deletions(-)","diff":"diff --git a/audio/mixeng_template.h b/audio/mixeng_template.h\nindex 5b0014bdd9af..6db742188eda 100644\n--- a/audio/mixeng_template.h\n+++ b/audio/mixeng_template.h\n@@ -28,7 +28,7 @@\n */\n \n #ifndef SIGNED\n-#define HALF (IN_MAX >> 1)\n+#define BIAS ((IN_T)1 << (SHIFT - 1))\n #endif\n \n #define ET glue (ENDIAN_CONVERSION, glue (glue (glue (_, ITYPE), BSIZE), _t))\n@@ -43,13 +43,13 @@ static inline mixeng_real glue (conv_, ET) (IN_T v)\n #ifdef SIGNED\n return nv * (2.f / ((mixeng_real)IN_MAX - IN_MIN));\n #else\n- return ((mixeng_real)nv - HALF) * (2.f / (mixeng_real)IN_MAX);\n+ return ((mixeng_real)nv - BIAS) * (1.f / BIAS);\n #endif\n #else /* !RECIPROCAL */\n #ifdef SIGNED\n return nv / (((mixeng_real)IN_MAX - IN_MIN) / 2.f);\n #else\n- return ((mixeng_real)nv - HALF) / ((mixeng_real)IN_MAX / 2.f);\n+ return ((mixeng_real)nv - BIAS) / BIAS;\n #endif\n #endif\n }\n@@ -65,9 +65,7 @@ static inline IN_T glue (clip_, ET) (mixeng_real v)\n #ifdef SIGNED\n return ENDIAN_CONVERT((IN_T)(v * (((mixeng_real)IN_MAX - IN_MIN) / 2.f)));\n #else\n- return ENDIAN_CONVERT(MIN((int64_t)((v * ((mixeng_real)IN_MAX / 2.f)) +\n- HALF),\n- IN_MAX));\n+ return ENDIAN_CONVERT(MIN((int64_t)(v * BIAS) + BIAS, IN_MAX));\n #endif\n }\n \n@@ -79,7 +77,7 @@ static inline int64_t glue (conv_, ET) (IN_T v)\n #ifdef SIGNED\n return ((int64_t) nv) << (32 - SHIFT);\n #else\n- return ((int64_t) nv - HALF) << (32 - SHIFT);\n+ return ((int64_t) nv - BIAS) << (32 - SHIFT);\n #endif\n }\n \n@@ -94,7 +92,7 @@ static inline IN_T glue (clip_, ET) (int64_t v)\n #ifdef SIGNED\n return ENDIAN_CONVERT ((IN_T) (v >> (32 - SHIFT)));\n #else\n- return ENDIAN_CONVERT ((IN_T) ((v >> (32 - SHIFT)) + HALF));\n+ return ENDIAN_CONVERT((IN_T)((v >> (32 - SHIFT)) + BIAS));\n #endif\n }\n #endif\n@@ -150,5 +148,5 @@ static void glue (glue (clip_, ET), _from_mono)\n }\n \n #undef ET\n-#undef HALF\n+#undef BIAS\n #undef IN_T\n","prefixes":["3/3"]}