Example #1
0
/* check if the provided BOS page is the start of a vorbis stream. If so
 * then setup a structure so it can be used
 */
ogg_codec_t *initial_vorbis_page (format_plugin_t *plugin, ogg_page *page)
{
    ogg_state_t *ogg_info = plugin->_state;
    ogg_codec_t *codec = calloc (1, sizeof (ogg_codec_t));
    ogg_packet packet;

    vorbis_codec_t *vorbis = calloc (1, sizeof (vorbis_codec_t));

    ogg_stream_init (&codec->os, ogg_page_serialno (page));
    ogg_stream_pagein (&codec->os, page);

    vorbis_info_init (&vorbis->vi);
    vorbis_comment_init (&vorbis->vc);

    ogg_stream_packetout (&codec->os, &packet);

    DEBUG0("checking for vorbis codec");
    if (vorbis_synthesis_headerin (&vorbis->vi, &vorbis->vc, &packet) < 0)
    {
        ogg_stream_clear (&codec->os);
        vorbis_info_clear (&vorbis->vi);
        vorbis_comment_clear (&vorbis->vc);
        free (vorbis);
        free (codec);
        return NULL;
    }
    INFO0 ("seen initial vorbis header");
    codec->specific = vorbis;
    codec->codec_free = vorbis_codec_free;
    codec->headers = 1;
    codec->parent = ogg_info;
    codec->name = "Vorbis";

    free_ogg_packet (vorbis->header[0]);
    free_ogg_packet (vorbis->header[1]);
    free_ogg_packet (vorbis->header[2]);
    memset (vorbis->header, 0, sizeof (vorbis->header));
    vorbis->header [0] = copy_ogg_packet (&packet);
    ogg_stream_init (&vorbis->new_os, rand());

    codec->process_page = process_vorbis_page;
    codec->process = process_vorbis;
    plugin->set_tag = vorbis_set_tag;

    vorbis->bos_page.header = malloc (page->header_len + page->body_len);

    memcpy (vorbis->bos_page.header, page->header, page->header_len);
    vorbis->bos_page.header_len = page->header_len;

    vorbis->bos_page.body = vorbis->bos_page.header + page->header_len;
    memcpy (vorbis->bos_page.body, page->body, page->body_len);
    vorbis->bos_page.body_len = page->body_len;

    return codec;
}
/* process the vorbis audio packets. Here we just take each packet out 
 * and add them into the new stream, flushing after so many samples. We
 * also check if an new headers are requested after each processed page
 */
static int process_vorbis_audio (ogg_state_t *ogg_info, ogg_codec_t *codec)
{
    vorbis_codec_t *source_vorbis = codec->specific;

    while (1)
    {
        int window;
        ogg_packet packet;

        /* now, lets extract what packets we can */
        if (ogg_stream_packetout (&codec->os, &packet) <= 0)
            break;

        /* calculate granulepos for the packet */
        window = vorbis_packet_blocksize (&source_vorbis->vi, &packet) / 4;

        source_vorbis->granulepos += window;
        if (source_vorbis->prev_packet)
        {
            ogg_packet *prev_packet = source_vorbis->prev_packet;

            add_audio_packet (source_vorbis, prev_packet);
            free_ogg_packet (prev_packet);
            packet . granulepos = source_vorbis->granulepos;
        }
        else
        {
            packet . granulepos = 0;
        }

        /* store the current packet details */
        source_vorbis->prev_window = window;
        source_vorbis->prev_packet = copy_ogg_packet (&packet);
        if (packet.e_o_s)
        {
            initiate_flush (source_vorbis);
            free_ogg_packet (source_vorbis->prev_packet);
            source_vorbis->prev_packet = NULL;
            return 1;
        }

        /* allow for pages to be flushed if there's over a certain number of samples */
        if (source_vorbis->samples_in_page > source_vorbis->page_samples_trigger)
            return 1;
    }
    if (source_vorbis->stream_notify)
    {
        initiate_flush (source_vorbis);
        source_vorbis->stream_notify = 0;
        return 1;
    }
    return -1;
}
/* handle incoming page. as the stream is being rebuilt, we need to
 * add all pages from the stream before processing packets
 */
static refbuf_t *process_vorbis_page (ogg_state_t *ogg_info,
        ogg_codec_t *codec, ogg_page *page)
{
    ogg_packet header;
    vorbis_codec_t *source_vorbis = codec->specific;
    char *comment;

    if (ogg_stream_pagein (&codec->os, page) < 0)
    {
        ogg_info->error = 1;
        return NULL;
    }
    if (codec->headers == 3)
        return NULL;

    while (codec->headers < 3)
    {
        /* now, lets extract the packets */
        DEBUG1 ("processing incoming header packet (%d)", codec->headers);

        if (ogg_stream_packetout (&codec->os, &header) <= 0)
        {
            if (ogg_info->codecs->next)
                format_ogg_attach_header (ogg_info, page);
            return NULL;
        }

        /* change comments here if need be */
        if (vorbis_synthesis_headerin (&source_vorbis->vi, &source_vorbis->vc, &header) < 0)
        {
            ogg_info->error = 1;
            WARN0 ("Problem parsing ogg vorbis header");
            return NULL;
        }
        header.granulepos = 0;
        source_vorbis->header [codec->headers] = copy_ogg_packet (&header);
        codec->headers++;
    }
    DEBUG0 ("we have the header packets now");

    /* if vorbis is the only codec then allow rebuilding of the streams */
    if (ogg_info->codecs->next == NULL)
    {
        /* set queued vorbis pages to contain about 1/2 of a second worth of samples */
        source_vorbis->page_samples_trigger = source_vorbis->vi.rate / 2;
        source_vorbis->process_packet = process_vorbis_headers;
    }
    else
    {
        format_ogg_attach_header (ogg_info, &source_vorbis->bos_page);
        format_ogg_attach_header (ogg_info, page);
        codec->process_page = process_vorbis_passthru_page;
    }

    free (ogg_info->title);
    comment = vorbis_comment_query (&source_vorbis->vc, "TITLE", 0);
    if (comment)
        ogg_info->title = strdup (comment);
    else
        ogg_info->title = NULL;

    free (ogg_info->artist);
    comment = vorbis_comment_query (&source_vorbis->vc, "ARTIST", 0);
    if (comment)
        ogg_info->artist = strdup (comment);
    else
        ogg_info->artist = NULL;
    ogg_info->log_metadata = 1;

    stats_event_args (ogg_info->mount, "audio_samplerate", "%ld", (long)source_vorbis->vi.rate);
    stats_event_args (ogg_info->mount, "audio_channels", "%ld", (long)source_vorbis->vi.channels);
    stats_event_args (ogg_info->mount, "audio_bitrate", "%ld", (long)source_vorbis->vi.bitrate_nominal);
    stats_event_args (ogg_info->mount, "ice-bitrate", "%ld", (long)source_vorbis->vi.bitrate_nominal/1000);

    return NULL;
}