mmap_begin callback is used to copy data from input file to mmaped buffer

guard for corner use of api (multiple mmap_begin calls by user) is introduced to check if next continuous buffer was already overwritten

buffer is overwritten with input file data only in case of stream capture

Signed-off-by: Adam Miartus amiartus@de.adit-jv.com Reviewed-by: Timo Wischer twischer@de.adit-jv.com

diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c index 10d227b..7d3439a 100644 --- a/src/pcm/pcm_file.c +++ b/src/pcm/pcm_file.c @@ -88,6 +88,7 @@ typedef struct { size_t buffer_bytes; struct wav_fmt wav_header; size_t filelen; + char ifmmap_overwritten; } snd_pcm_file_t;

#if __BYTE_ORDER == __LITTLE_ENDIAN @@ -626,6 +627,8 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm, const snd_pcm_channel_area_t *areas; snd_pcm_sframes_t result;

+ file->ifmmap_overwritten = 0; + result = snd_pcm_mmap_begin(file->gen.slave, &areas, &ofs, &siz); if (result >= 0) { assert(ofs == offset && siz == size); @@ -636,6 +639,32 @@ static snd_pcm_sframes_t snd_pcm_file_mmap_commit(snd_pcm_t *pcm, return result; }

+static int snd_pcm_file_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas, + snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames) +{ + snd_pcm_file_t *file = pcm->private_data; + snd_pcm_channel_area_t areas_if[pcm->channels]; + snd_pcm_uframes_t frames_if; + void *buffer = NULL; + int result; + + result = snd_pcm_mmap_begin(file->gen.slave, areas, offset, frames); + if (result < 0) + return result; + + if (pcm->stream != SND_PCM_STREAM_CAPTURE) + return result; + + /* user may run mmap_begin without mmap_commit multiple times in row */ + if (file->ifmmap_overwritten) + return result; + file->ifmmap_overwritten = 1; + + snd_pcm_file_areas_read_infile(pcm, *areas, *offset, *frames); + + return result; +} + static int snd_pcm_file_hw_free(snd_pcm_t *pcm) { snd_pcm_file_t *file = pcm->private_data; @@ -662,6 +691,7 @@ static int snd_pcm_file_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params) file->wbuf_size = slave->buffer_size * 2; file->wbuf_size_bytes = snd_pcm_frames_to_bytes(slave, file->wbuf_size); file->wbuf_used_bytes = 0; + file->ifmmap_overwritten = 0; assert(!file->wbuf); file->wbuf = malloc(file->wbuf_size_bytes); if (file->wbuf == NULL) { @@ -773,7 +803,7 @@ static const snd_pcm_fast_ops_t snd_pcm_file_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_generic_poll_revents, .htimestamp = snd_pcm_generic_htimestamp, - .mmap_begin = NULL, + .mmap_begin = snd_pcm_file_mmap_begin, };

/**