From afc7d62d02c523f3d3adc29f713f5a4395ca3f58 Mon Sep 17 00:00:00 2001 From: Thierry Bultel Date: Tue, 17 Jul 2018 09:16:27 +0200 Subject: alsa-core-pcm: sets sw start & stop thresholds Uses the same logic as 'aplay' to set the start & stop thresholds. With this fix, there are no more periodic EPIPE errors when writing to playback Signed-off-by: Thierry Bultel --- plugins/alsa/alsa-core-pcm.c | 102 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 90 insertions(+), 12 deletions(-) (limited to 'plugins/alsa') diff --git a/plugins/alsa/alsa-core-pcm.c b/plugins/alsa/alsa-core-pcm.c index 885d2bf..e672429 100644 --- a/plugins/alsa/alsa-core-pcm.c +++ b/plugins/alsa/alsa-core-pcm.c @@ -147,13 +147,18 @@ PUBLIC int AlsaPcmConf(SoftMixerT *mixer, AlsaPcmCtlT *pcm, int mode) { }; } - int err; + /* The following code, that + * 1) sets period time/size; buffer time/size hardware params + * 2) sets start and stop threashold in software params + * ... is taken as such from 'aplay' in alsa-utils */ + unsigned buffer_time = 0; unsigned period_time = 0; snd_pcm_uframes_t buffer_frames = 0; snd_pcm_uframes_t period_frames = 0; - err = snd_pcm_hw_params_get_buffer_time_max(pxmHwParams, &buffer_time, 0); + error = snd_pcm_hw_params_get_buffer_time_max(pxmHwParams, &buffer_time, 0); + if (buffer_time > 500000) buffer_time = 500000; @@ -163,25 +168,36 @@ PUBLIC int AlsaPcmConf(SoftMixerT *mixer, AlsaPcmCtlT *pcm, int mode) { else period_frames = buffer_frames / 4; } + if (period_time > 0) - err = snd_pcm_hw_params_set_period_time_near(pcm->handle, pxmHwParams, &period_time, 0); + error = snd_pcm_hw_params_set_period_time_near(pcm->handle, pxmHwParams, &period_time, 0); else - err = snd_pcm_hw_params_set_period_size_near(pcm->handle, pxmHwParams, &period_frames, 0); + error = snd_pcm_hw_params_set_period_size_near(pcm->handle, pxmHwParams, &period_frames, 0); - assert(err >= 0); + if (error < 0) { + AFB_ApiError(mixer->api, + "%s: mixer=%s cardid=%s Fail to set period in hwparams error=%s", + __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); + goto OnErrorExit; + } if (buffer_time > 0) { - err = snd_pcm_hw_params_set_buffer_time_near(pcm->handle, pxmHwParams, &buffer_time, 0); + error = snd_pcm_hw_params_set_buffer_time_near(pcm->handle, pxmHwParams, &buffer_time, 0); } else { - err = snd_pcm_hw_params_set_buffer_size_near(pcm->handle, pxmHwParams, &buffer_frames); + error = snd_pcm_hw_params_set_buffer_size_near(pcm->handle, pxmHwParams, &buffer_frames); } - assert(err >= 0); + if (error < 0) { + AFB_ApiError(mixer->api, + "%s: mixer=%s cardid=%s Fail to set buffer in hwparams error=%s", + __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); + goto OnErrorExit; + } // store selected values if ((error = snd_pcm_hw_params(pcm->handle, pxmHwParams)) < 0) { AFB_ApiError(mixer->api, - "%s: mixer=%s cardid=%s Fail apply hwparams error=%s", + "%s: mixer=%s cardid=%s Fail to apply hwparams error=%s", __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); goto OnErrorExit; } @@ -193,6 +209,9 @@ PUBLIC int AlsaPcmConf(SoftMixerT *mixer, AlsaPcmCtlT *pcm, int mode) { snd_pcm_hw_params_get_channels(pxmHwParams, &opts->channels); snd_pcm_hw_params_get_format(pxmHwParams, &opts->format); snd_pcm_hw_params_get_rate(pxmHwParams, &opts->rate, 0); + + AFB_ApiInfo(mixer->api, "rate is %d", opts->rate); + opts->sampleSize = AlsaPeriodSize(opts->format); if (opts->sampleSize == 0) { AFB_ApiError(mixer->api, @@ -201,17 +220,77 @@ PUBLIC int AlsaPcmConf(SoftMixerT *mixer, AlsaPcmCtlT *pcm, int mode) { goto OnErrorExit; } + snd_pcm_uframes_t chunk_size, buffer_size; + + snd_pcm_hw_params_get_period_size(pxmHwParams, &chunk_size, 0); + snd_pcm_hw_params_get_buffer_size(pxmHwParams, &buffer_size); + if (chunk_size == buffer_size) { + AFB_ApiError(mixer->api, + "Can't use period equal to buffer size (%lu == %lu)", + chunk_size, buffer_size); + goto OnErrorExit; + } + + int avail_min = -1; + size_t n; + int rate = opts->rate; + + if (avail_min < 0) + n = chunk_size; + else + n = (size_t) ((double)rate * avail_min / 1000000); + // retrieve software config from PCM snd_pcm_sw_params_alloca(&pxmSwParams); snd_pcm_sw_params_current(pcm->handle, pxmSwParams); - if ((error = snd_pcm_sw_params_set_avail_min(pcm->handle, pxmSwParams, 6000)) < 0) { + if ((error = snd_pcm_sw_params_set_avail_min(pcm->handle, pxmSwParams, n)) < 0) { AFB_ApiError(mixer->api, "%s: mixer=%s cardid=%s Fail set_buffersize error=%s", __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); goto OnErrorExit; }; + int start_delay = 0; + int stop_delay = 0; + snd_pcm_uframes_t start_threshold, stop_threshold; + + /* round up to closest transfer boundary */ + n = buffer_size; + if (start_delay <= 0) { + start_threshold = n + (size_t)((double)rate * start_delay / 1000000); + } else + start_threshold = (size_t)((double)rate * start_delay / 1000000); + if (start_threshold < 1) + start_threshold = 1; + + if (start_threshold > n) + start_threshold = n; + + AFB_ApiInfo(mixer->api, "Set start threshold to %ld", start_threshold); + + error = snd_pcm_sw_params_set_start_threshold(pcm->handle, pxmSwParams, start_threshold); + if (error < 0) { + AFB_ApiError(mixer->api, + "%s: mixer=%s cardid=%s failed set start_threshold, error=%s", + __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); + goto OnErrorExit; + } + + if (stop_delay <= 0) + stop_threshold = buffer_size + (size_t)((double)rate * stop_delay / 1000000); + else + stop_threshold = (size_t)((double)rate * stop_delay / 1000000); + + AFB_ApiInfo(mixer->api, "Set stop threshold to %ld", stop_threshold); + error = snd_pcm_sw_params_set_stop_threshold(pcm->handle, pxmSwParams, stop_threshold); + if (error < 0) { + AFB_ApiError(mixer->api, + "%s: mixer=%s cardid=%s failed set stop_threshold, error=%s", + __func__, mixer->uid, pcm->cid.cardid, snd_strerror(error)); + goto OnErrorExit; + } + // push software params into PCM if ((error = snd_pcm_sw_params(pcm->handle, pxmSwParams)) < 0) { AFB_ApiError(mixer->api, @@ -221,7 +300,7 @@ PUBLIC int AlsaPcmConf(SoftMixerT *mixer, AlsaPcmCtlT *pcm, int mode) { }; AFB_ApiNotice(mixer->api, - "%s: mixer=%s cardid=%s Done channels=%d rate=%d format=%d access=%d done", + "%s: mixer=%s cardid=%s Done channels=%d rate=%d format=%d access=%d ... done !", __func__, mixer->uid, pcm->cid.cardid, opts->channels, opts->rate, opts->format, opts->access); return 0; @@ -322,7 +401,6 @@ STATIC int AlsaPcmReadCB( struct pollfd * pfd, AlsaPcmCopyHandleT * pcmCopyHandl } if (availOut == 0) { - printf("No space on playback\n"); goto ExitOnSuccess; } -- cgit 1.2.3-korg