rtmp: Rename packet types to closer match the spec

Also rename comments and log messages accordingly,
and add clarifying comments for some hardcoded values.

The previous names were taken from older, reverse engineered
references.

These names match the official public rtmp specification, and
matches the names used by wirecast in annotating captured
streams. These names also avoid hardcoding the roles of server
and client, since the handling of them is irrelevant of whether
we act as server or client.

The RTMP_PT_PING type maps to RTMP_PT_USER_CONTROL.

The SERVER_BW and CLIENT_BW types are a bit more intertwined;
RTMP_PT_SERVER_BW maps to RTMP_PT_WINDOW_ACK_SIZE and
RTMP_PT_CLIENT_BW maps to RTMP_PT_SET_PEER_BW.

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

3 files changed, 43 insertions, 43 deletions

diff --git a/libavformat/rtmppkt.c b/libavformat/rtmppkt.c
index 1cb3078679..0bb06143b5 100644
--- a/libavformat/rtmppkt.c
+++ b/libavformat/rtmppkt.c
@@ -527,9 +527,9 @@ static const char* rtmp_packet_type(int type)
     switch (type) {
     case RTMP_PT_CHUNK_SIZE:     return "chunk size";
     case RTMP_PT_BYTES_READ:     return "bytes read";
-    case RTMP_PT_PING:           return "ping";
-    case RTMP_PT_SERVER_BW:      return "server bandwidth";
-    case RTMP_PT_CLIENT_BW:      return "client bandwidth";
+    case RTMP_PT_USER_CONTROL:   return "user control";
+    case RTMP_PT_WINDOW_ACK_SIZE: return "window acknowledgement size";
+    case RTMP_PT_SET_PEER_BW:    return "set peer bandwidth";
     case RTMP_PT_AUDIO:          return "audio packet";
     case RTMP_PT_VIDEO:          return "video packet";
     case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
@@ -627,10 +627,10 @@ void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
                 break;
             src += sz;
         }
-    } else if (p->type == RTMP_PT_SERVER_BW){
-        av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
-    } else if (p->type == RTMP_PT_CLIENT_BW){
-        av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
+    } else if (p->type == RTMP_PT_WINDOW_ACK_SIZE) {
+        av_log(ctx, AV_LOG_DEBUG, "Window acknowledgement size = %d\n", AV_RB32(p->data));
+    } else if (p->type == RTMP_PT_SET_PEER_BW) {
+        av_log(ctx, AV_LOG_DEBUG, "Set Peer BW = %d\n", AV_RB32(p->data));
     } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
         int i;
         for (i = 0; i < p->size; i++)
diff --git a/libavformat/rtmppkt.h b/libavformat/rtmppkt.h
index 149c153cad..eccd299b24 100644
--- a/libavformat/rtmppkt.h
+++ b/libavformat/rtmppkt.h
@@ -47,9 +47,9 @@ enum RTMPChannel {
 typedef enum RTMPPacketType {
     RTMP_PT_CHUNK_SIZE   =  1,  ///< chunk size change
     RTMP_PT_BYTES_READ   =  3,  ///< number of bytes read
-    RTMP_PT_PING,               ///< ping
-    RTMP_PT_SERVER_BW,          ///< server bandwidth
-    RTMP_PT_CLIENT_BW,          ///< client bandwidth
+    RTMP_PT_USER_CONTROL,       ///< user control
+    RTMP_PT_WINDOW_ACK_SIZE,    ///< window acknowledgement size
+    RTMP_PT_SET_PEER_BW,        ///< peer bandwidth
     RTMP_PT_AUDIO        =  8,  ///< audio packet
     RTMP_PT_VIDEO,              ///< video packet
     RTMP_PT_FLEX_STREAM  = 15,  ///< Flex shared stream
diff --git a/libavformat/rtmpproto.c b/libavformat/rtmpproto.c
index 49a40dd66a..d0a36139cc 100644
--- a/libavformat/rtmpproto.c
+++ b/libavformat/rtmpproto.c
@@ -453,7 +453,7 @@ static int read_connect(URLContext *s, RTMPContext *rt)
 
     // Send Window Acknowledgement Size (as defined in specification)
     if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL,
-                                     RTMP_PT_SERVER_BW, 0, 4)) < 0)
+                                     RTMP_PT_WINDOW_ACK_SIZE, 0, 4)) < 0)
         return ret;
     p = pkt.data;
     bytestream_put_be32(&p, rt->server_bw);
@@ -463,9 +463,9 @@ static int read_connect(URLContext *s, RTMPContext *rt)
     ff_rtmp_packet_destroy(&pkt);
     if (ret < 0)
         return ret;
-    // Send Peer Bandwidth
+    // Set Peer Bandwidth
     if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL,
-                                     RTMP_PT_CLIENT_BW, 0, 5)) < 0)
+                                     RTMP_PT_SET_PEER_BW, 0, 5)) < 0)
         return ret;
     p = pkt.data;
     bytestream_put_be32(&p, rt->server_bw);
@@ -477,14 +477,14 @@ static int read_connect(URLContext *s, RTMPContext *rt)
     if (ret < 0)
         return ret;
 
-    // Ping request
+    // User control
     if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL,
-                                     RTMP_PT_PING, 0, 6)) < 0)
+                                     RTMP_PT_USER_CONTROL, 0, 6)) < 0)
         return ret;
 
     p = pkt.data;
     bytestream_put_be16(&p, 0); // 0 -> Stream Begin
-    bytestream_put_be32(&p, 0);
+    bytestream_put_be32(&p, 0); // Stream 0
     ret = ff_rtmp_packet_write(rt->stream, &pkt, rt->out_chunk_size,
                                &rt->prev_pkt[1], &rt->nb_prev_pkt[1]);
     ff_rtmp_packet_destroy(&pkt);
@@ -710,12 +710,12 @@ static int gen_buffer_time(URLContext *s, RTMPContext *rt)
     uint8_t *p;
     int ret;
 
-    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_PING,
+    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_USER_CONTROL,
                                      1, 10)) < 0)
         return ret;
 
     p = pkt.data;
-    bytestream_put_be16(&p, 3);
+    bytestream_put_be16(&p, 3); // SetBuffer Length
     bytestream_put_be32(&p, rt->stream_id);
     bytestream_put_be32(&p, rt->client_buffer_time);
 
@@ -842,12 +842,12 @@ static int gen_pong(URLContext *s, RTMPContext *rt, RTMPPacket *ppkt)
         return AVERROR_INVALIDDATA;
     }
 
-    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_PING,
+    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL,RTMP_PT_USER_CONTROL,
                                      ppkt->timestamp + 1, 6)) < 0)
         return ret;
 
     p = pkt.data;
-    bytestream_put_be16(&p, 7);
+    bytestream_put_be16(&p, 7); // PingResponse
     bytestream_put_be32(&p, AV_RB32(ppkt->data+2));
 
     return rtmp_send_packet(rt, &pkt, 0);
@@ -863,7 +863,7 @@ static int gen_swf_verification(URLContext *s, RTMPContext *rt)
     int ret;
 
     av_log(s, AV_LOG_DEBUG, "Sending SWF verification...\n");
-    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_PING,
+    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_USER_CONTROL,
                                      0, 44)) < 0)
         return ret;
 
@@ -875,15 +875,15 @@ static int gen_swf_verification(URLContext *s, RTMPContext *rt)
 }
 
 /**
- * Generate server bandwidth message and send it to the server.
+ * Generate window acknowledgement size message and send it to the server.
  */
-static int gen_server_bw(URLContext *s, RTMPContext *rt)
+static int gen_window_ack_size(URLContext *s, RTMPContext *rt)
 {
     RTMPPacket pkt;
     uint8_t *p;
     int ret;
 
-    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_SERVER_BW,
+    if ((ret = ff_rtmp_packet_create(&pkt, RTMP_NETWORK_CHANNEL, RTMP_PT_WINDOW_ACK_SIZE,
                                      0, 4)) < 0)
         return ret;
 
@@ -1520,19 +1520,19 @@ static int handle_chunk_size(URLContext *s, RTMPPacket *pkt)
     return 0;
 }
 
-static int handle_ping(URLContext *s, RTMPPacket *pkt)
+static int handle_user_control(URLContext *s, RTMPPacket *pkt)
 {
     RTMPContext *rt = s->priv_data;
     int t, ret;
 
     if (pkt->size < 2) {
-        av_log(s, AV_LOG_ERROR, "Too short ping packet (%d)\n",
+        av_log(s, AV_LOG_ERROR, "Too short user control packet (%d)\n",
                pkt->size);
         return AVERROR_INVALIDDATA;
     }
 
     t = AV_RB16(pkt->data);
-    if (t == 6) {
+    if (t == 6) { // PingRequest
         if ((ret = gen_pong(s, rt, pkt)) < 0)
             return ret;
     } else if (t == 26) {
@@ -1547,48 +1547,48 @@ static int handle_ping(URLContext *s, RTMPPacket *pkt)
     return 0;
 }
 
-static int handle_client_bw(URLContext *s, RTMPPacket *pkt)
+static int handle_set_peer_bw(URLContext *s, RTMPPacket *pkt)
 {
     RTMPContext *rt = s->priv_data;
 
     if (pkt->size < 4) {
         av_log(s, AV_LOG_ERROR,
-               "Client bandwidth report packet is less than 4 bytes long (%d)\n",
+               "Peer bandwidth packet is less than 4 bytes long (%d)\n",
                pkt->size);
         return AVERROR_INVALIDDATA;
     }
 
     rt->client_report_size = AV_RB32(pkt->data);
     if (rt->client_report_size <= 0) {
-        av_log(s, AV_LOG_ERROR, "Incorrect client bandwidth %d\n",
+        av_log(s, AV_LOG_ERROR, "Incorrect peer bandwidth %d\n",
                 rt->client_report_size);
         return AVERROR_INVALIDDATA;
 
     }
-    av_log(s, AV_LOG_DEBUG, "Client bandwidth = %d\n", rt->client_report_size);
+    av_log(s, AV_LOG_DEBUG, "Peer bandwidth = %d\n", rt->client_report_size);
     rt->client_report_size >>= 1;
 
     return 0;
 }
 
-static int handle_server_bw(URLContext *s, RTMPPacket *pkt)
+static int handle_window_ack_size(URLContext *s, RTMPPacket *pkt)
 {
     RTMPContext *rt = s->priv_data;
 
     if (pkt->size < 4) {
         av_log(s, AV_LOG_ERROR,
-               "Too short server bandwidth report packet (%d)\n",
+               "Too short window acknowledgement size packet (%d)\n",
                pkt->size);
         return AVERROR_INVALIDDATA;
     }
 
     rt->server_bw = AV_RB32(pkt->data);
     if (rt->server_bw <= 0) {
-        av_log(s, AV_LOG_ERROR, "Incorrect server bandwidth %d\n",
+        av_log(s, AV_LOG_ERROR, "Incorrect window acknowledgement size %d\n",
                rt->server_bw);
         return AVERROR_INVALIDDATA;
     }
-    av_log(s, AV_LOG_DEBUG, "Server bandwidth = %d\n", rt->server_bw);
+    av_log(s, AV_LOG_DEBUG, "Window acknowledgement size = %d\n", rt->server_bw);
 
     return 0;
 }
@@ -1825,7 +1825,7 @@ static int write_begin(URLContext *s)
 
     // Send Stream Begin 1
     if ((ret = ff_rtmp_packet_create(&spkt, RTMP_NETWORK_CHANNEL,
-                                     RTMP_PT_PING, 0, 6)) < 0) {
+                                     RTMP_PT_USER_CONTROL, 0, 6)) < 0) {
         av_log(s, AV_LOG_ERROR, "Unable to create response packet\n");
         return ret;
     }
@@ -2053,7 +2053,7 @@ static int handle_invoke_result(URLContext *s, RTMPPacket *pkt)
             if ((ret = gen_fcpublish_stream(s, rt)) < 0)
                 goto fail;
         } else {
-            if ((ret = gen_server_bw(s, rt)) < 0)
+            if ((ret = gen_window_ack_size(s, rt)) < 0)
                 goto fail;
         }
 
@@ -2302,16 +2302,16 @@ static int rtmp_parse_result(URLContext *s, RTMPContext *rt, RTMPPacket *pkt)
         if ((ret = handle_chunk_size(s, pkt)) < 0)
             return ret;
         break;
-    case RTMP_PT_PING:
-        if ((ret = handle_ping(s, pkt)) < 0)
+    case RTMP_PT_USER_CONTROL:
+        if ((ret = handle_user_control(s, pkt)) < 0)
             return ret;
         break;
-    case RTMP_PT_CLIENT_BW:
-        if ((ret = handle_client_bw(s, pkt)) < 0)
+    case RTMP_PT_SET_PEER_BW:
+        if ((ret = handle_set_peer_bw(s, pkt)) < 0)
             return ret;
         break;
-    case RTMP_PT_SERVER_BW:
-        if ((ret = handle_server_bw(s, pkt)) < 0)
+    case RTMP_PT_WINDOW_ACK_SIZE:
+        if ((ret = handle_window_ack_size(s, pkt)) < 0)
             return ret;
         break;
     case RTMP_PT_INVOKE: