From patchwork Tue Mar 1 19:13:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Volker_R=C3=BCmelin?= X-Patchwork-Id: 12765088 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 80181C433EF for ; Tue, 1 Mar 2022 19:19:50 +0000 (UTC) Received: from localhost ([::1]:49514 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nP82H-0001xV-KG for qemu-devel@archiver.kernel.org; Tue, 01 Mar 2022 14:19:49 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43258) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nP7wB-0005EW-Qc for qemu-devel@nongnu.org; Tue, 01 Mar 2022 14:13:31 -0500 Received: from mailout06.t-online.de ([194.25.134.19]:60730) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nP7w9-0001pJ-Fm for qemu-devel@nongnu.org; Tue, 01 Mar 2022 14:13:31 -0500 Received: from fwd76.dcpf.telekom.de (fwd76.aul.t-online.de [10.223.144.102]) by mailout06.t-online.de (Postfix) with SMTP id F299819706; Tue, 1 Mar 2022 20:13:27 +0100 (CET) Received: from linpower.localnet ([46.86.48.20]) by fwd76.t-online.de with (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384 encrypted) esmtp id 1nP7w7-1FmMgj0; Tue, 1 Mar 2022 20:13:27 +0100 Received: by linpower.localnet (Postfix, from userid 1000) id 0490420061A; Tue, 1 Mar 2022 20:13:12 +0100 (CET) From: =?utf-8?q?Volker_R=C3=BCmelin?= To: Gerd Hoffmann Subject: [PATCH v3 07/15] audio: copy playback stream in sequential order Date: Tue, 1 Mar 2022 20:13:03 +0100 Message-Id: <20220301191311.26695-7-vr_qemu@t-online.de> X-Mailer: git-send-email 2.34.1 In-Reply-To: <3d0bd2ac-e5b9-9cf6-c98f-c047390a3ec5@t-online.de> References: <3d0bd2ac-e5b9-9cf6-c98f-c047390a3ec5@t-online.de> MIME-Version: 1.0 X-TOI-EXPURGATEID: 150726::1646162007-0001619A-2F59D5AB/0/0 CLEAN NORMAL X-TOI-MSGID: 7c0b4836-a17f-463d-9f14-4cb96b636700 Received-SPF: none client-ip=194.25.134.19; envelope-from=volker.ruemelin@t-online.de; helo=mailout06.t-online.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christian Schoenebeck , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Change the code to copy the playback stream in sequential order. The advantage can be seen in the next patches where the stream copy operation effectively becomes a write through operation. The following diagram shows the average buffer fill level and the stream copy sequence. ### represents a timer_period sized chunk. The rest of the buffer sizes are not to scale. With current code: |--------| |#####111| |---#####| sw->buf mix_buf backend buffer 1. clip |--------| |---#####| |111##222| sw->buf mix_buf backend buffer 2. write to audio device 333 -> |--------| |---#####| |---111##| -> 222 sw->buf mix_buf backend buffer 3a. sw device write |-----333| |---#####| |---111##| sw->buf mix_buf backend buffer 3b. resample and mix |--------| |333#####| |---111##| sw->buf mix_buf backend buffer With this patch: 111 -> |--------| |---#####| |---#####| sw->buf mix_buf backend buffer 1a: sw device write |-----111| |---#####| |---#####| sw->buf mix_buf backend buffer 1b. resample and mix |--------| |111##222| |---#####| sw->buf mix_buf backend buffer 2. clip |--------| |---111##| |222##333| sw->buf mix_buf backend buffer 3. write to audio device |--------| |---111##| |---222##| -> 333 sw->buf mix_buf backend buffer The effective total playback buffer size is reduced by timer_period. Signed-off-by: Volker Rümelin --- audio/audio.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/audio/audio.c b/audio/audio.c index 35437986d9..9e2d7fb209 100644 --- a/audio/audio.c +++ b/audio/audio.c @@ -1134,6 +1134,15 @@ static void audio_run_out (AudioState *s) size_t played, live, prev_rpos, free; int nb_live; + for (sw = hw->sw_head.lh_first; sw; sw = sw->entries.le_next) { + if (sw->active) { + free = audio_get_free(sw); + if (free > 0) { + sw->callback.fn(sw->callback.opaque, free); + } + } + } + live = audio_pcm_hw_get_live_out (hw, &nb_live); if (!nb_live) { live = 0; @@ -1162,14 +1171,6 @@ static void audio_run_out (AudioState *s) } if (!live) { - for (sw = hw->sw_head.lh_first; sw; sw = sw->entries.le_next) { - if (sw->active) { - free = audio_get_free (sw); - if (free > 0) { - sw->callback.fn (sw->callback.opaque, free); - } - } - } if (hw->pcm_ops->run_buffer_out) { hw->pcm_ops->run_buffer_out(hw); } @@ -1210,13 +1211,6 @@ static void audio_run_out (AudioState *s) if (!sw->total_hw_samples_mixed) { sw->empty = 1; } - - if (sw->active) { - free = audio_get_free (sw); - if (free > 0) { - sw->callback.fn (sw->callback.opaque, free); - } - } } } }