ffmpeg-hls拉流代码

ffmpeg-hls拉流

协议接口变量

const URLProtocol ff_hls_protocol = {
    .name           = "hls",
    .url_open       = hls_open,
    .url_read       = hls_read,
    .url_close      = hls_close,
    .flags          = URL_PROTOCOL_FLAG_NESTED_SCHEME,
    .priv_data_size = sizeof(HLSContext),
};

从上面可以看出来一共就三个接口，打开，读取，关闭

打开

static int hls_open(URLContext *h, const char *uri, int flags)
{
    HLSContext *s = h->priv_data;
    int ret, i;
    const char *nested_url;

    if (flags & AVIO_FLAG_WRITE)
        return AVERROR(ENOSYS);

    h->is_streamed = 1;

    if (av_strstart(uri, "hls+", &nested_url)) {
        av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
    } else if (av_strstart(uri, "hls://", &nested_url)) {
        av_log(h, AV_LOG_ERROR,
               "No nested protocol specified. Specify e.g. hls+http://%s\n",
               nested_url);
        ret = AVERROR(EINVAL);
        goto fail;
    } else {
        av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
        ret = AVERROR(EINVAL);
        goto fail;
    }
    av_log(h, AV_LOG_WARNING,
           "Using the hls protocol is discouraged, please try using the "
           "hls demuxer instead. The hls demuxer should be more complete "
           "and work as well as the protocol implementation. (If not, "
           "please report it.) To use the demuxer, simply use %s as url.\n",
           s->playlisturl);

    if ((ret = parse_playlist(h, s->playlisturl)) < 0)
        goto fail;

    if (s->n_segments == 0 && s->n_variants > 0) {
        int max_bandwidth = 0, maxvar = -1;
        for (i = 0; i < s->n_variants; i++) {
            if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
                max_bandwidth = s->variants[i]->bandwidth;
                maxvar = i;
            }
        }
        av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
                   sizeof(s->playlisturl));
        if ((ret = parse_playlist(h, s->playlisturl)) < 0)
            goto fail;
    }

    if (s->n_segments == 0) {
        av_log(h, AV_LOG_WARNING, "Empty playlist\n");
        ret = AVERROR(EIO);
        goto fail;
    }
    s->cur_seq_no = s->start_seq_no;
    if (!s->finished && s->n_segments >= 3)
        s->cur_seq_no = s->start_seq_no + s->n_segments - 3;

    return 0;

fail:
    hls_close(h);
    return ret;
}

open主要是读取m3u8的信息，并存储到变量中