smf.c

VLC Player Source Code

        return -1;

    length = ReadVarInt (s);
    if (length < 0)
        return -1;

    payload = malloc (length + 1);
    if ((payload == NULL)
     || (stream_Read (s, payload, length) != length))
    {
        free (payload);
        return -1;
    }

    payload[length] = '\0';

    switch (type)
    {
        case 0x00: /* Sequence Number */
            break;

        case 0x01: /* Text (comment) */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Text      : %s", (char *)payload);
            break;

        case 0x02: /* Copyright */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Copyright : %s", (char *)payload);
            break;

        case 0x03: /* Track name */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Track name: %s", (char *)payload);
            break;

        case 0x04: /* Instrument name */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Instrument: %s", (char *)payload);
            break;

        case 0x05: /* Lyric (one syllable) */
            /*EnsureUTF8 ((char *)payload);*/
            break;

        case 0x06: /* Marker text */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Marker    : %s", (char *)payload);

        case 0x07: /* Cue point (WAVE filename) */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Cue point : %s", (char *)payload);
            break;

        case 0x08: /* Program/Patch name */
            EnsureUTF8 ((char *)payload);
            msg_Info (p_demux, "Patch name: %s", (char *)payload);
            break;

        case 0x09: /* MIDI port name */
            EnsureUTF8 ((char *)payload);
            msg_Dbg (p_demux, "MIDI port : %s", (char *)payload);
            break;

        case 0x2F: /* End of track */
            if (tr->end != stream_Tell (s))
            {
                msg_Err (p_demux, "misplaced end of track");
                ret = -1;
            }
            break;

        case 0x51: /* Tempo */
            if (length == 3)
            {
                uint32_t uspqn = (payload[0] << 16)
                               | (payload[1] << 8) | payload[2];
                unsigned tempo = 60 * 1000000 / (uspqn ? uspqn : 1);
                msg_Dbg (p_demux, "tempo: %uus/qn -> %u BPM",
                         (unsigned)uspqn, tempo);

                if (tempo < TEMPO_MIN)
                {
                    msg_Warn (p_demux, "tempo too slow -> %u BPM", TEMPO_MIN);
                    tempo = TEMPO_MIN;
                }
                else
                if (tempo > TEMPO_MAX)
                {
                    msg_Warn (p_demux, "tempo too fast -> %u BPM", TEMPO_MAX);
                    tempo = TEMPO_MAX;
                }
                date_Change (&p_sys->pts, p_sys->ppqn * tempo, 60);
            }
            else
                ret = -1;
            break;

        case 0x54: /* SMPTE offset */
            if (length == 5)
                msg_Warn (p_demux, "SMPTE offset not implemented");
            else
                ret = -1;
            break;

        case 0x58: /* Time signature */
            if (length == 4)
                ;
            else
                ret = -1;
            break;

        case 0x59: /* Key signature */
            if (length == 2)
                ;
            else
                ret = -1;
            break;

        case 0x7f: /* Proprietary event */
            msg_Dbg (p_demux, "ignored proprietary SMF Meta Event (%d bytes)",
                     length);
            break;

        default:
            msg_Warn (p_demux, "unknown SMF Meta Event type 0x%02X (%d bytes)",
                      type, length);
    }

    free (payload);
    return 0;
}



static
int HandleMessage (demux_t *p_demux, mtrk_t *tr)
{
    stream_t *s = p_demux->s;
    block_t *block;
    uint8_t first, event;
    unsigned datalen;

    if (stream_Seek (s, tr->offset)
     || (stream_Read (s, &first, 1) != 1))
        return -1;

    event = (first & 0x80) ? first : tr->running_event;

    switch (event & 0xf0)
    {
        case 0xF0: /* System Exclusive */
            switch (event)
            {
                case 0xF0: /* System Specific */
                {
                    /* TODO: don't skip these */
                    stream_Read (s, NULL, 1); /* Manuf ID */
                    for (;;)
                    {
                        uint8_t c;
                        if (stream_Read (s, &c, 1) != 1)
                            return -1;
                        if (c == 0xF7)
                            goto skip;
                    }
                    /* never reached */
                }
                case 0xFF: /* SMF Meta Event */
                    if (HandleMeta (p_demux, tr))
                        return -1;
                    /* We MUST NOT pass this event forward. It would be
                     * confused as a MIDI Reset real-time event. */
                    goto skip;
                case 0xF1:
                case 0xF3:
                    datalen = 1;
                    break;
                case 0xF2:
                    datalen = 2;
                    break;
                case 0xF4:
                case 0xF5:
                    /* We cannot handle undefined "common" (non-real-time)
                     * events inside SMF, as we cannot differentiate a
                     * one byte delta-time (< 0x80) from event data. */
                case 0xF7: /* End of sysex -> should never happen(?) */
                    msg_Err (p_demux, "unknown MIDI event 0x%02X", event);
                    return -1; /* undefined events */
                default:
                    datalen = 0;
                    break;
            }
        case 0xC0:
        case 0xD0:
            datalen = 1;
            break;
        default:
            datalen = 2;
            break;
    }

    /* FIXME: one message per block is very inefficient */
    block = block_New (p_demux, 1 + datalen);
    if (block == NULL)
        goto skip;

    block->p_buffer[0] = event;
    if (first & 0x80)
    {
        stream_Read (s, block->p_buffer + 1, datalen);
    }
    else
    {
        if (datalen == 0)
        {
            msg_Err (p_demux, "malformatted MIDI event");
            return -1; /* can't use implicit running status with empty payload! */
        }

        block->p_buffer[1] = first;
        if (datalen > 1)
            stream_Read (s, block->p_buffer + 2, datalen - 1);
    }

    block->i_dts = block->i_pts = date_Get (&p_demux->p_sys->pts);
    es_out_Send (p_demux->out, p_demux->p_sys->es, block);

skip:
    if (event < 0xF8)
        /* If event is not real-time, update running status */
        tr->running_event = event;

    tr->offset = stream_Tell (s);
    return 0;
}

/*****************************************************************************
 * Demux: read chunks and send them to the synthetizer
 *****************************************************************************
 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 *****************************************************************************/
static int Demux (demux_t *p_demux)
{
    stream_t *s = p_demux->s;
    demux_sys_t *p_sys = p_demux->p_sys;
    uint64_t     pulse = p_sys->pulse, next_pulse = UINT64_MAX;

    if (pulse == UINT64_MAX)
        return 0; /* all tracks are done */

    es_out_Control (p_demux->out, ES_OUT_SET_PCR, date_Get (&p_sys->pts));

    for (unsigned i = 0; i < p_sys->trackc; i++)
    {
        mtrk_t *track = p_sys->trackv + i;

        while (track->next == pulse)
        {
            if (HandleMessage (p_demux, track)
             || ReadDeltaTime (s, track))
            {
                msg_Err (p_demux, "fatal parsing error");
                return VLC_EGENERIC;
            }
        }

        if (track->next < next_pulse)
            next_pulse = track->next;
    }

    mtime_t cur_tick = (date_Get (&p_sys->pts) + 9999) / 10000, last_tick;
    if (next_pulse != UINT64_MAX)
        last_tick = date_Increment (&p_sys->pts, next_pulse - pulse) / 10000;
    else
        last_tick = cur_tick + 1;

    /* MIDI Tick emulation (ping the decoder every 10ms) */
    while (cur_tick < last_tick)
    {
        block_t *tick = block_New (p_demux, 1);
        if (tick == NULL)
            break;

        tick->p_buffer[0] = 0xF9;
        tick->i_dts = tick->i_pts = cur_tick++ * 10000;
        es_out_Send (p_demux->out, p_sys->es, tick);
    }

    p_sys->pulse = next_pulse;

    return 1;
}


/*****************************************************************************
 * Control:
 *****************************************************************************/
static int Control (demux_t *p_demux, int i_query, va_list args)
{
    demux_sys_t *p_sys = p_demux->p_sys;

    switch (i_query)
    {
        case DEMUX_GET_TIME:
        {
            *(va_arg (args, int64_t *)) = date_Get (&p_sys->pts);
            return 0;
        }
#if 0
        /* TODO: */
        case DEMUX_SET_TIME:
        case DEMUX_GET_POSITION:
        case DEMUX_SET_POSITION:
        case DEMUX_GET_LENGTH:
#endif
    }
    return VLC_EGENERIC;
}