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[2620:137:e000::1:20]) by mx.google.com with ESMTP id na3-20020a17090b4c0300b00246bb27b5ffsi5204811pjb.109.2023.04.13.06.55.28; Thu, 13 Apr 2023 06:55:41 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20221208 header.b=L6w5otXI; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231365AbjDMNuV (ORCPT + 99 others); Thu, 13 Apr 2023 09:50:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230149AbjDMNuT (ORCPT ); Thu, 13 Apr 2023 09:50:19 -0400 Received: from mail-yw1-x112f.google.com (mail-yw1-x112f.google.com [IPv6:2607:f8b0:4864:20::112f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84D5D7280; Thu, 13 Apr 2023 06:50:04 -0700 (PDT) Received: by mail-yw1-x112f.google.com with SMTP id 00721157ae682-54fbee98814so34788827b3.8; Thu, 13 Apr 2023 06:50:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1681393803; x=1683985803; h=cc:to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=me/aMOzykgZd/rQWir4A2t1w//OGU8Q3sKZmPgaxe3w=; b=L6w5otXIHyI2IbOVWI9zFAmYPFxav9f5v27dXrrRH5HzftZ+oIBUdCXz/CXcq12RZK /uxMw4zvD1cr7CPBX5VkAuLku7Csi2L9kUR8s5hSavTTtFO6c1Q7p8j/IShwjeXZ3/e0 /6XxUhegy5rZurXznROgvK/yQI1ndV1AdK+/HTneWQlrgs7Sjz8zhnXeQEKoHid1LHWK rej8qf/u8enxGMKgKXMT7VcTCYpfuW/0n1bgRZlGK0ry9fPPE+uO/3WL/VgOspLH/+9P oAEBBGoTla0VCEK2cx2VuMcjujESdZ9fRkAgT9v1oIj9FapE0mgylJzG1/fU24vEMChx pJ6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681393803; x=1683985803; h=cc:to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=me/aMOzykgZd/rQWir4A2t1w//OGU8Q3sKZmPgaxe3w=; b=HRayYSlNRhsbGz2ArQ80AN5DDCLiHlYHnafqZJ2gzJ6SHDeuwgnHyqcvaYzuNnrJUE bAlC0F9zCra4IsC4nks4EYtm6AN2OI/kYhX5m7RWsdlwQcZvVjDsY/CctOJTzi4RgUfS N9nvHd27wl5neqsc9HpchtYH+dJIrcrLLsh+OZlOj7liap1hlIrn9C0J+ia4qmhgHLd9 N/Ipn4kfmXYYpcNKcbY6Wnv3MOX3OtDu2vj3Keer9KXL0HU4s7rhSm0hmWb0N5JiJLc9 DHUvdPJGMAX+QuTz2xJEv0R0UQPwjxoc6fIlJAT4uib2U9bDSd/dYDgtKtZHlrWFR9+B pZJg== X-Gm-Message-State: AAQBX9dhzjwyvUDWGAz1LllY7w8rfxZN1IgOWKbRq2KGWCINbanQUhVW m35tGyhYVBaFgSbDgUOtvyu+ynhH+bCNEogP32t/pTAc9ZY= X-Received: by 2002:a81:7613:0:b0:54f:b9f8:70ae with SMTP id r19-20020a817613000000b0054fb9f870aemr1470541ywc.7.1681393803597; Thu, 13 Apr 2023 06:50:03 -0700 (PDT) MIME-Version: 1.0 From: Muni Sekhar Date: Thu, 13 Apr 2023 19:19:52 +0530 Message-ID: Subject: ALSA: arecord : silennce recorded as 0x80 To: alsa-devel , linux-sound@vger.kernel.org Cc: LKML , kernelnewbies Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, I recorded the silence on the default audio card by running "arecord -d 5 test.wav." Once it exited, I checked the contents by running "hexdump test.wav," and I see that silence is recorded as a sequence of 0x80 instead of 0x00. 0000000 4952 4646 0024 8000 4157 4556 6d66 2074 0000010 0010 0000 0001 0001 1f40 0000 1f40 0000 0000020 0001 0008 6164 6174 0000 8000 8080 8080 0000030 8080 8080 8080 8080 8080 8080 8080 8080 0000040 8080 8080 8080 8080 8080 8080 8080 8080 ... What might be the reason for silence being recorded as 0x80 instead of 0x0? -- Thanks, Sekhar