RTMPT protocol support

This adds two protocols, but one of them is an internal implementation
detail just used as an abstraction layer/generalization in the code. The
RTMPT protocol implementation uses rtmphttp:// as an alternative to the
tcp:// protocol. This allows moving most of the lower level logic out
from the higher level generic rtmp code.

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 239 insertions, 0 deletions

diff --git a/libavformat/rtmphttp.c b/libavformat/rtmphttp.c
new file mode 100644
index 0000000000..fdcff50bed
--- /dev/null
+++ b/libavformat/rtmphttp.c
@@ -0,0 +1,239 @@
+/*
+ * RTMP HTTP network protocol
+ * Copyright (c) 2012 Samuel Pitoiset
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * RTMP HTTP protocol
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/intfloat.h"
+#include "libavutil/opt.h"
+#include "internal.h"
+#include "http.h"
+
+#define RTMPT_DEFAULT_PORT 80
+
+/* protocol handler context */
+typedef struct RTMP_HTTPContext {
+    URLContext   *stream;           ///< HTTP stream
+    char         host[256];         ///< hostname of the server
+    int          port;              ///< port to connect (default is 80)
+    char         client_id[64];     ///< client ID used for all requests except the first one
+    int          seq;               ///< sequence ID used for all requests
+    uint8_t      *out_data;         ///< output buffer
+    int          out_size;          ///< current output buffer size
+    int          out_capacity;      ///< current output buffer capacity
+    int          initialized;       ///< flag indicating when the http context is initialized
+    int          finishing;         ///< flag indicating when the client closes the connection
+} RTMP_HTTPContext;
+
+static int rtmp_http_send_cmd(URLContext *h, const char *cmd)
+{
+    RTMP_HTTPContext *rt = h->priv_data;
+    char uri[2048];
+    uint8_t c;
+    int ret;
+
+    ff_url_join(uri, sizeof(uri), "http", NULL, rt->host, rt->port,
+                "/%s/%s/%d", cmd, rt->client_id, rt->seq++);
+
+    av_opt_set_bin(rt->stream->priv_data, "post_data", rt->out_data,
+                   rt->out_size, 0);
+
+    /* send a new request to the server */
+    if ((ret = ff_http_do_new_request(rt->stream, uri)) < 0)
+        return ret;
+
+    /* re-init output buffer */
+    rt->out_size = 0;
+
+    /* read the first byte which contains the polling interval */
+    if ((ret = ffurl_read(rt->stream, &c, 1)) < 0)
+        return ret;
+
+    return ret;
+}
+
+static int rtmp_http_write(URLContext *h, const uint8_t *buf, int size)
+{
+    RTMP_HTTPContext *rt = h->priv_data;
+    void *ptr;
+
+    if (rt->out_size + size > rt->out_capacity) {
+        rt->out_capacity = (rt->out_size + size) * 2;
+        ptr = av_realloc(rt->out_data, rt->out_capacity);
+        if (!ptr)
+            return AVERROR(ENOMEM);
+        rt->out_data = ptr;
+    }
+
+    memcpy(rt->out_data + rt->out_size, buf, size);
+    rt->out_size += size;
+
+    return size;
+}
+
+static int rtmp_http_read(URLContext *h, uint8_t *buf, int size)
+{
+    RTMP_HTTPContext *rt = h->priv_data;
+    int ret, off = 0;
+
+    /* try to read at least 1 byte of data */
+    do {
+        ret = ffurl_read(rt->stream, buf + off, size);
+        if (ret < 0 && ret != AVERROR_EOF)
+            return ret;
+
+        if (ret == AVERROR_EOF) {
+            if (rt->finishing) {
+                /* Do not send new requests when the client wants to
+                 * close the connection. */
+                return AVERROR(EAGAIN);
+            }
+
+            /* When the client has reached end of file for the last request,
+             * we have to send a new request if we have buffered data.
+             * Otherwise, we have to send an idle POST. */
+            if (rt->out_size > 0) {
+                if ((ret = rtmp_http_send_cmd(h, "send")) < 0)
+                    return ret;
+            } else {
+                if ((ret = rtmp_http_write(h, "", 1)) < 0)
+                    return ret;
+
+                if ((ret = rtmp_http_send_cmd(h, "idle")) < 0)
+                    return ret;
+            }
+
+            if (h->flags & AVIO_FLAG_NONBLOCK) {
+                /* no incoming data to handle in nonblocking mode */
+                return AVERROR(EAGAIN);
+            }
+        } else {
+            off  += ret;
+            size -= ret;
+        }
+    } while (off <= 0);
+
+    return off;
+}
+
+static int rtmp_http_close(URLContext *h)
+{
+    RTMP_HTTPContext *rt = h->priv_data;
+    uint8_t tmp_buf[2048];
+    int ret = 0;
+
+    if (rt->initialized) {
+        /* client wants to close the connection */
+        rt->finishing = 1;
+
+        do {
+            ret = rtmp_http_read(h, tmp_buf, sizeof(tmp_buf));
+        } while (ret > 0);
+
+        /* re-init output buffer before sending the close command */
+        rt->out_size = 0;
+
+        if ((ret = rtmp_http_write(h, "", 1)) == 1)
+            ret = rtmp_http_send_cmd(h, "close");
+    }
+
+    av_freep(&rt->out_data);
+    ffurl_close(rt->stream);
+
+    return ret;
+}
+
+static int rtmp_http_open(URLContext *h, const char *uri, int flags)
+{
+    RTMP_HTTPContext *rt = h->priv_data;
+    char headers[1024], url[1024];
+    int ret, off = 0;
+
+    av_url_split(NULL, 0, NULL, 0, rt->host, sizeof(rt->host), &rt->port,
+                 NULL, 0, uri);
+
+    if (rt->port < 0)
+        rt->port = RTMPT_DEFAULT_PORT;
+
+    /* This is the first request that is sent to the server in order to
+     * register a client on the server and start a new session. The server
+     * replies with a unique id (usually a number) that is used by the client
+     * for all future requests.
+     * Note: the reply doesn't contain a value for the polling interval.
+     * A successful connect resets the consecutive index that is used
+     * in the URLs. */
+    ff_url_join(url, sizeof(url), "http", NULL, rt->host, rt->port, "/open/1");
+
+    /* alloc the http context */
+    if ((ret = ffurl_alloc(&rt->stream, url, AVIO_FLAG_READ_WRITE, NULL)) < 0)
+        goto fail;
+
+    /* set options */
+    snprintf(headers, sizeof(headers),
+             "Cache-Control: no-cache\r\n"
+             "Content-type: application/x-fcs\r\n"
+             "User-Agent: Shockwave Flash\r\n");
+    av_opt_set(rt->stream->priv_data, "headers", headers, 0);
+    av_opt_set(rt->stream->priv_data, "multiple_requests", "1", 0);
+    av_opt_set_bin(rt->stream->priv_data, "post_data", "", 1, 0);
+
+    /* open the http context */
+    if ((ret = ffurl_connect(rt->stream, NULL)) < 0)
+        goto fail;
+
+    /* read the server reply which contains a unique ID */
+    for (;;) {
+        ret = ffurl_read(rt->stream, rt->client_id + off, sizeof(rt->client_id) - off);
+        if (ret == AVERROR_EOF)
+            break;
+        if (ret < 0)
+            goto fail;
+        off += ret;
+        if (off == sizeof(rt->client_id)) {
+            ret = AVERROR(EIO);
+            goto fail;
+        }
+    }
+    while (off > 0 && isspace(rt->client_id[off - 1]))
+        off--;
+    rt->client_id[off] = '\0';
+
+    /* http context is now initialized */
+    rt->initialized = 1;
+    return 0;
+
+fail:
+    rtmp_http_close(h);
+    return ret;
+}
+
+URLProtocol ff_rtmphttp_protocol = {
+    .name           = "rtmphttp",
+    .url_open       = rtmp_http_open,
+    .url_read       = rtmp_http_read,
+    .url_write      = rtmp_http_write,
+    .url_close      = rtmp_http_close,
+    .priv_data_size = sizeof(RTMP_HTTPContext),
+    .flags          = URL_PROTOCOL_FLAG_NETWORK,
+};