From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8DF3C388F9 for ; Fri, 23 Oct 2020 09:10:35 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 100A1241A4 for ; Fri, 23 Oct 2020 09:10:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="kjtOAQWo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 100A1241A4 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=alsa-project.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 434B717F3; Fri, 23 Oct 2020 11:09:40 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 434B717F3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1603444230; bh=HmKv+ISk63qJXZOq/5Sp5uQA2xZwr+T0jibyIFHo7To=; h=From:To:In-Reply-To:References:Subject:Date:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=kjtOAQWolxdbpqhyBrFQoX3dzzCGCA+7pBz/CSsrXotDgjM8EOVRn07W65N4FFAwj 8Olvt2gJ7Kt+XgPkwXoXYNcrniuvenN9gGSNL1aE0cGeS2IpegiTj+FoRAJF6BJX+M 02lVjoyENIu0V9iB6zKZBr70rizhC4TcK+EawutA= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 8B355F80247; Fri, 23 Oct 2020 11:09:39 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id D39F0F800BD; Fri, 23 Oct 2020 11:09:38 +0200 (CEST) Received: from webhooks-bot.alsa-project.org (gate.perex.cz [77.48.224.242]) by alsa1.perex.cz (Postfix) with ESMTP id 1A965F800BD for ; Fri, 23 Oct 2020 11:09:32 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 1A965F800BD MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit From: GitHub pull_request - opened To: alsa-devel@alsa-project.org In-Reply-To: <1603444171719347000-webhooks-bot@alsa-project.org> References: <1603444171719347000-webhooks-bot@alsa-project.org> Subject: aplay: try to use 16-bit format to increase capture quality Message-Id: <20201023090938.D39F0F800BD@alsa1.perex.cz> Date: Fri, 23 Oct 2020 11:09:38 +0200 (CEST) X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" alsa-project/alsa-utils pull request #69 was opened from jason77-wang: Recently users reported a bug, I tested it and found it is a common issue on Laptop or Desktop machines. The issue is users plug a headset and use "arecord test.wav" to record a sound with default input volume, the recorded sound has poor quality and nearly can't distinguish it is the sound we want to record. This is because the input volume is low and the default format is U8. The driver records sound with 16bit, because the input volume is low, most of samples are within (-256,+256), when converting 16bit to U8, those samples will be 0x7f. This is called quantization noise and we could only workaround it by increase the input volume or adding -f to arecord. But users want to record a better quality sound with default input volume (after installing a new OS, the volume is the default volume), and they don't want to add parameters to the arecord because most of new linux users just use "arecord test.wav". So this patch tries to change the default format from U8 to S16_LE/BE. If the machine doesn't support S16_LE/BE, it still uses U8 as default format. Signed-off-by: Hui Wang Request URL : https://github.com/alsa-project/alsa-utils/pull/69 Patch URL : https://github.com/alsa-project/alsa-utils/pull/69.patch Repository URL: https://github.com/alsa-project/alsa-utils