From 1c49c5f19e53cf29ae3356c0f0b3b124d44a3664 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Volker=20R=C3=BCmelin?= Date: Fri, 24 Feb 2023 20:05:50 +0100 Subject: [PATCH] audio: replace the resampling loop in audio_pcm_sw_read() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Replace the resampling loop in audio_pcm_sw_read() with the new function audio_pcm_sw_resample_in(). Unlike the old resample loop the new function will try to consume input frames even if the output buffer is full. This is necessary when downsampling to avoid reading less audio frames than calculated in advance. The loop was unrolled to avoid complicated loop control conditions in this case. Acked-by: Mark Cave-Ayland Acked-by: Marc-André Lureau Signed-off-by: Volker Rümelin Message-Id: <20230224190555.7409-10-vr_qemu@t-online.de> --- audio/audio.c | 59 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 24 deletions(-) diff --git a/audio/audio.c b/audio/audio.c index e18b5e98c5..9e9c03a42e 100644 --- a/audio/audio.c +++ b/audio/audio.c @@ -543,11 +543,43 @@ static size_t audio_pcm_hw_conv_in(HWVoiceIn *hw, void *pcm_buf, size_t samples) /* * Soft voice (capture) */ +static void audio_pcm_sw_resample_in(SWVoiceIn *sw, + size_t frames_in_max, size_t frames_out_max, + size_t *total_in, size_t *total_out) +{ + HWVoiceIn *hw = sw->hw; + struct st_sample *src, *dst; + size_t live, rpos, frames_in, frames_out; + + live = hw->total_samples_captured - sw->total_hw_samples_acquired; + rpos = audio_ring_posb(hw->conv_buf.pos, live, hw->conv_buf.size); + + /* resample conv_buf from rpos to end of buffer */ + src = hw->conv_buf.buffer + rpos; + frames_in = MIN(frames_in_max, hw->conv_buf.size - rpos); + dst = sw->resample_buf.buffer; + frames_out = frames_out_max; + st_rate_flow(sw->rate, src, dst, &frames_in, &frames_out); + rpos += frames_in; + *total_in = frames_in; + *total_out = frames_out; + + /* resample conv_buf from start of buffer if there are input frames left */ + if (frames_in_max - frames_in && rpos == hw->conv_buf.size) { + src = hw->conv_buf.buffer; + frames_in = frames_in_max - frames_in; + dst += frames_out; + frames_out = frames_out_max - frames_out; + st_rate_flow(sw->rate, src, dst, &frames_in, &frames_out); + *total_in += frames_in; + *total_out += frames_out; + } +} + static size_t audio_pcm_sw_read(SWVoiceIn *sw, void *buf, size_t size) { HWVoiceIn *hw = sw->hw; - size_t samples, live, ret = 0, swlim, isamp, osamp, rpos, total = 0; - struct st_sample *src, *dst = sw->resample_buf.buffer; + size_t samples, live, ret, swlim, total; live = hw->total_samples_captured - sw->total_hw_samples_acquired; if (!live) { @@ -558,33 +590,12 @@ static size_t audio_pcm_sw_read(SWVoiceIn *sw, void *buf, size_t size) return 0; } - rpos = audio_ring_posb(hw->conv_buf.pos, live, hw->conv_buf.size); - samples = size / sw->info.bytes_per_frame; swlim = (live * sw->ratio) >> 32; swlim = MIN (swlim, samples); - while (swlim) { - src = hw->conv_buf.buffer + rpos; - if (hw->conv_buf.pos > rpos) { - isamp = hw->conv_buf.pos - rpos; - } else { - isamp = hw->conv_buf.size - rpos; - } - - if (!isamp) { - break; - } - osamp = swlim; - - st_rate_flow (sw->rate, src, dst, &isamp, &osamp); - swlim -= osamp; - rpos = (rpos + isamp) % hw->conv_buf.size; - dst += osamp; - ret += osamp; - total += isamp; - } + audio_pcm_sw_resample_in(sw, live, swlim, &total, &ret); if (!hw->pcm_ops->volume_in) { mixeng_volume(sw->resample_buf.buffer, ret, &sw->vol);