Hi Tedd,
On Fri, Jun 19, 2020 at 9:27 PM <tedd.an@xxxxxxxxxxxxxxx> wrote:
>
> From: Tedd Ho-Jeong An <tedd.an@xxxxxxxxx>
>
> The SysEx end of message parser didn't consider the fact that
> timestampsLow are in the stream and it might have the EOX (F7)
> byte as well.
>
> Fix that by always assuming the first system message byte is
> the timestampLow.
>
> Future work would involve support other type of system message
> bytes, such as real-time.
> ---
> profiles/midi/libmidi.c | 38 +++++++++++++++++++++++++++++++-------
> 1 file changed, 31 insertions(+), 7 deletions(-)
>
> diff --git a/profiles/midi/libmidi.c b/profiles/midi/libmidi.c
> index 4b4df799f..7d57e7335 100644
> --- a/profiles/midi/libmidi.c
> +++ b/profiles/midi/libmidi.c
> @@ -331,6 +331,30 @@ static size_t handle_end_of_sysex(struct midi_read_parser *parser,
> return sysex_length + 1; /* +1 because of timestampLow */
> }
>
> +/* Searches the end of a SysEx message that contains a timestampLow
> + * before the SysEx end byte. Returns the number of bytes of valid
> + * SysEx payload in the buffer.
> + */
> +static size_t sysex_eox_len(const uint8_t *data, size_t size)
> +{
> + size_t i = 0;
> +
> + MIDI_ASSERT(size > 0);
> +
> + if (data[i] == 0xF0)
> + i++;
> +
> + /* Search for timestamp low */
> + while (i < size) {
> + if ((data[i] & 0x80)) {
> + i++;
> + break;
> + }
> + i++;
> + }
> +
> + return (i < size && data[i] == 0xF7) ? i : 0;
> +}
>
>
> size_t midi_read_raw(struct midi_read_parser *parser, const uint8_t *data,
> @@ -368,14 +392,14 @@ size_t midi_read_raw(struct midi_read_parser *parser, const uint8_t *data,
>
> /* System Common Messages */
> case 0xF0: /* SysEx Start */ {
> - uint8_t *pos;
> + size_t sysex_length;
>
> /* cleanup Running Status Message */
> parser->rstatus = 0;
>
> - /* Avoid parsing if SysEx is contained in one BLE packet */
> - if ((pos = memchr(data + i, 0xF7, size - i))) {
> - const size_t sysex_length = pos - (data + i);
> + sysex_length = sysex_eox_len(data + i, size - i);
> + /* Search for End of SysEx message in one BLE message */
> + if (sysex_length > 0) {
> midi_size = handle_end_of_sysex(parser, ev, data + i,
> sysex_length);
> } else {
> @@ -424,10 +448,10 @@ size_t midi_read_raw(struct midi_read_parser *parser, const uint8_t *data,
>
> /* Check for SysEx messages */
> if (parser->sysex_stream.len > 0) {
> - uint8_t *pos;
> + size_t sysex_length;
>
> - if ((pos = memchr(data + i, 0xF7, size - i))) {
> - const size_t sysex_length = pos - (data + i);
> + sysex_length = sysex_eox_len(data + i, size - i);
> + if (sysex_length > 0) {
> midi_size = handle_end_of_sysex(parser, ev, data + i,
> sysex_length);
> } else {
> --
> 2.25.4
>
Applied, thanks.
--
Luiz Augusto von Dentz
