diff options
| author | Jeff Epler <jepler@gmail.com> | 2019-12-24 09:43:15 -0600 |
|---|---|---|
| committer | Jeff Epler <jepler@gmail.com> | 2019-12-24 09:43:15 -0600 |
| commit | 97bb46c0471b5cb9a0323f06183945d4c711207b (patch) | |
| tree | 2375fc38ea2282959f175c4391ba4f5d3819959b | |
| parent | 5aa3e3eabb90bb9845204b2287e311d5923d30a5 (diff) | |
MP3File: tweak buffer handling
After adding the ability to change files in an existing MP3File object,
it became apparent that at the beginning of a track some part of an
existing buffer was playing first.
I noticed that in get_buffer, the just-populated buffer wasn't being
returned, but the other one was. But still after fixing this, I heard
wrong audio at the beginning of a track, so I took the heavy duty approach
and zeroed the buffers out. That means there's a remaining bug to chase,
which is merely hidden by the memset()s.
| -rw-r--r-- | shared-module/audiomp3/MP3File.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/shared-module/audiomp3/MP3File.c b/shared-module/audiomp3/MP3File.c index 549fbcdc0..390ba2544 100644 --- a/shared-module/audiomp3/MP3File.c +++ b/shared-module/audiomp3/MP3File.c @@ -215,6 +215,13 @@ void common_hal_audiomp3_mp3file_set_file(audiomp3_mp3file_obj_t* self, pyb_file self->other_channel = -1; mp3file_update_inbuf(self); mp3file_find_sync_word(self); + // It **SHOULD** not be necessary to do this; the buffer should be filled + // with fresh content before it is returned by get_buffer(). The fact that + // this is necessary to avoid a glitch at the start of playback of a second + // track using the same decoder object means there's still a bug in + // get_buffer() that I didn't understand. + memset(self->buffers[0], 0, MAX_BUFFER_LEN); + memset(self->buffers[1], 0, MAX_BUFFER_LEN); MP3FrameInfo fi; if(!mp3file_get_next_frame_info(self, &fi)) { mp_raise_msg(&mp_type_RuntimeError, @@ -290,7 +297,6 @@ audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t* channel = 0; } - *bufptr = (uint8_t*)(self->buffers[self->buffer_index] + channel); *buffer_length = self->frame_buffer_size; if (channel == self->other_channel) { @@ -299,11 +305,12 @@ audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t* return GET_BUFFER_MORE_DATA; } - self->other_channel = 1-channel; - self->other_buffer_index = self->buffer_index; self->buffer_index = !self->buffer_index; + self->other_channel = 1-channel; + self->other_buffer_index = self->buffer_index; int16_t *buffer = (int16_t *)(void *)self->buffers[self->buffer_index]; + *bufptr = (uint8_t*)buffer; mp3file_skip_id3v2(self); if (!mp3file_find_sync_word(self)) { |