From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <ffmpeg-devel-bounces@ffmpeg.org>
Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100])
	by master.gitmailbox.com (Postfix) with ESMTP id 8DEB3462E0
	for <ffmpegdev@gitmailbox.com>; Fri, 14 Jul 2023 18:04:00 +0000 (UTC)
Received: from [127.0.1.1] (localhost [127.0.0.1])
	by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 45C1B68C636;
	Fri, 14 Jul 2023 21:03:50 +0300 (EEST)
Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net
 [217.70.183.201])
 by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 8B4B168C626
 for <ffmpeg-devel@ffmpeg.org>; Fri, 14 Jul 2023 21:03:44 +0300 (EEST)
Received: by mail.gandi.net (Postfix) with ESMTPSA id BF96D1BF204
 for <ffmpeg-devel@ffmpeg.org>; Fri, 14 Jul 2023 18:03:43 +0000 (UTC)
From: Michael Niedermayer <michael@niedermayer.cc>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Date: Fri, 14 Jul 2023 20:03:41 +0200
Message-Id: <20230714180341.2186605-2-michael@niedermayer.cc>
X-Mailer: git-send-email 2.31.1
In-Reply-To: <20230714180341.2186605-1-michael@niedermayer.cc>
References: <20230714180341.2186605-1-michael@niedermayer.cc>
MIME-Version: 1.0
X-GND-Sasl: michael@niedermayer.cc
Subject: [FFmpeg-devel] [PATCH 2/2] avradio/sdrdemux: Some corrections to
 the FM stereo side channel
X-BeenThere: ffmpeg-devel@ffmpeg.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: FFmpeg development discussions and patches <ffmpeg-devel.ffmpeg.org>
List-Unsubscribe: <https://ffmpeg.org/mailman/options/ffmpeg-devel>,
 <mailto:ffmpeg-devel-request@ffmpeg.org?subject=unsubscribe>
List-Archive: <https://ffmpeg.org/pipermail/ffmpeg-devel>
List-Post: <mailto:ffmpeg-devel@ffmpeg.org>
List-Help: <mailto:ffmpeg-devel-request@ffmpeg.org?subject=help>
List-Subscribe: <https://ffmpeg.org/mailman/listinfo/ffmpeg-devel>,
 <mailto:ffmpeg-devel-request@ffmpeg.org?subject=subscribe>
Reply-To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: ffmpeg-devel-bounces@ffmpeg.org
Sender: "ffmpeg-devel" <ffmpeg-devel-bounces@ffmpeg.org>
Archived-At: <https://master.gitmailbox.com/ffmpegdev/20230714180341.2186605-2-michael@niedermayer.cc/>
List-Archive: <https://master.gitmailbox.com/ffmpegdev/>
List-Post: <mailto:ffmpegdev@gitmailbox.com>

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavradio/sdrdemux.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libavradio/sdrdemux.c b/libavradio/sdrdemux.c
index 041775730e..5a6a9b8894 100644
--- a/libavradio/sdrdemux.c
+++ b/libavradio/sdrdemux.c
@@ -656,7 +656,7 @@ static av_always_inline void synchronous_am_demodulationN(AVComplexFloat *iblock
     for (int i = 0; i<len; i++) {
         AVComplexFloat c = icarrier[i];
         AVComplexFloat s = iblock[i];
-        float          w = window[i];
+        float          w = N == 2 ? 1.0 : window[i];
         AVComplexFloat c2= {c.re*c.re, c.im*c.im};
         float den        = w/(c2.re + c2.im);
 
@@ -1080,8 +1080,9 @@ static int demodulate_fm(SDRContext *sdr, Station *station, AVStream *st, AVPack
         newbuf[2*i+0]           = (sdr->fm_iblock[i + sdr->fm_block_size_p2].re) * sdr->fm_window_p2[i + sdr->fm_block_size_p2] * scale;
 
         if (carrier19_i >= 0) {
-            q = sst->out_buf[2*i+1] +  sdr->fm_iside[i                        ].im * sdr->fm_window_p2[i                        ] * scale;
-            newbuf[2*i+1]           =  sdr->fm_iside[i + sdr->fm_block_size_p2].im * sdr->fm_window_p2[i + sdr->fm_block_size_p2] * scale;
+            //the 0.5 is because we have both sides of the spectrum for iside
+            q = sst->out_buf[2*i+1] +  sdr->fm_iside[i                        ].im * sdr->fm_window_p2[i                        ] * (scale * 0.5);
+            newbuf[2*i+1]           =  sdr->fm_iside[i + sdr->fm_block_size_p2].im * sdr->fm_window_p2[i + sdr->fm_block_size_p2] * (scale * 0.5);
 
             sst->out_buf[2*i+0] = m + q;
             sst->out_buf[2*i+1] = m - q;
-- 
2.31.1

_______________________________________________
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".