From 8933882da9c63a0b60706828e11f3c09e2a903c7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Volker=20R=C3=BCmelin?= Date: Fri, 24 Feb 2023 20:05:43 +0100 Subject: [PATCH] audio: make the resampling code greedy MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Read the maximum possible number of audio frames instead of the minimum necessary number of frames when the audio stream is downsampled and the output buffer is limited. This makes the function symmetrical to upsampling when the input buffer is limited. The maximum possible number of frames is written here. With this change it's easier to calculate the exact number of audio frames the resample function will read or write. These two functions will be introduced later. Acked-by: Mark Cave-Ayland Acked-by: Marc-André Lureau Signed-off-by: Volker Rümelin Message-Id: <20230224190555.7409-3-vr_qemu@t-online.de> --- audio/rate_template.h | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/audio/rate_template.h b/audio/rate_template.h index b432719ebb..6648f0d2e5 100644 --- a/audio/rate_template.h +++ b/audio/rate_template.h @@ -40,8 +40,6 @@ void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf, int64_t t; #endif - ilast = rate->ilast; - istart = ibuf; iend = ibuf + *isamp; @@ -59,15 +57,17 @@ void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf, return; } - while (obuf < oend) { + /* without input samples, there's nothing to do */ + if (ibuf >= iend) { + *osamp = 0; + return; + } - /* Safety catch to make sure we have input samples. */ - if (ibuf >= iend) { - break; - } + ilast = rate->ilast; - /* read as many input samples so that ipos > opos */ + while (true) { + /* read as many input samples so that ipos > opos */ while (rate->ipos <= (rate->opos >> 32)) { ilast = *ibuf++; rate->ipos++; @@ -78,6 +78,11 @@ void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf, } } + /* make sure that the next output sample can be written */ + if (obuf >= oend) { + break; + } + icur = *ibuf; /* wrap ipos and opos around long before they overflow */ -- 2.30.2