[FFmpeg-devel] Add RTSP range header

[Yakov Okshtein]

Whoops, looks like Gmail sent the .patch file attachment as 
application/octet-stream ... I must say, the ffmpeg binary is much more 
lenient in its input than the ffmpeg-devel mailing list :)

Let me try again with Thunderbird, and a .txt file.

Thanks all,

Yakov

On 11/22/20 11:21 AM, Yakov Okshtein wrote:
> Hi all,
>
> While working to get historical video off a DVR, I found the lack of a 
> customizable Range: header for RTSP video frustrating (as, apparently, 
> have others on StackOverflow and the Trac wiki, #6659). One user 
> mentionedhaving made a custom patch, but didn't post it; so, I decided 
> to make one.
>
> It's my first submission to ffmpeg. I read the submission guidelines 
> and hope I didn't miss anything.
>
> Thanks all!
>
> Yakov
-------------- next part --------------
From 1c0a5ce96eef83bb3ed55a4dfa6e825668055cdb Mon Sep 17 00:00:00 2001
From: Yakov Okshtein <flyashi at gmail.com>
Date: Sun, 22 Nov 2020 16:06:46 +0000
Subject: [PATCH] Add optional Range and Rate-Control header to RTSP PLAY
 command

Some DVR/NVRs send historical video specified by the Range: header,
and can send files faster than real-time by the presence of the
Rate-Control: no header. This patch adds optional -range and
-rate_control CLI arguments, and if present, uses those values to
override the defaults.

Closes #6659
---
 libavformat/rtsp.c    |  2 ++
 libavformat/rtsp.h    | 10 ++++++++++
 libavformat/rtspdec.c | 15 +++++++++++----
 libavformat/rtspenc.c |  9 +++++++--
 4 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
index 0be405aba1..ca0b92251c 100644
--- a/libavformat/rtsp.c
+++ b/libavformat/rtsp.c
@@ -101,6 +101,8 @@ const AVOption ff_rtsp_options[] = {
 #endif
     COMMON_OPTS(),
     { "user_agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
+    { "range", "override Range header", OFFSET(range), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
+    { "rate_control", "override Rate-Control header", OFFSET(rate_control), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
 #if FF_API_OLD_RTSP_OPTIONS
     { "user-agent", "override User-Agent header (deprecated, use user_agent)", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, DEC },
 #endif
diff --git a/libavformat/rtsp.h b/libavformat/rtsp.h
index 251ed86d19..0778515045 100644
--- a/libavformat/rtsp.h
+++ b/libavformat/rtsp.h
@@ -409,6 +409,16 @@ typedef struct RTSPState {
      */
     char *user_agent;
 
+    /**
+     * Range header override; string.
+     */
+    char *range;
+
+    /**
+     * Rate-Control header; optional string.
+     */
+    char *rate_control;
+
     char default_lang[4];
     int buffer_size;
     int pkt_size;
diff --git a/libavformat/rtspdec.c b/libavformat/rtspdec.c
index 28b35d1993..0a0de21b82 100644
--- a/libavformat/rtspdec.c
+++ b/libavformat/rtspdec.c
@@ -541,11 +541,18 @@ static int rtsp_read_play(AVFormatContext *s)
         if (rt->state == RTSP_STATE_PAUSED) {
             cmd[0] = 0;
         } else {
-            snprintf(cmd, sizeof(cmd),
-                     "Range: npt=%"PRId64".%03"PRId64"-\r\n",
-                     rt->seek_timestamp / AV_TIME_BASE,
-                     rt->seek_timestamp / (AV_TIME_BASE / 1000) % 1000);
+           if (rt->range != NULL) {
+                snprintf(cmd, sizeof(cmd), "Range: %s\r\n", rt->range);
+           } else {
+                snprintf(cmd, sizeof(cmd),
+                         "Range: npt=%"PRId64".%03"PRId64"-\r\n",
+                         rt->seek_timestamp / AV_TIME_BASE,
+                         rt->seek_timestamp / (AV_TIME_BASE / 1000) % 1000);
+           }
         }
+       if (rt->rate_control != NULL) {
+           snprintf(cmd, sizeof(cmd), "Rate-Control: %s\r\n", rt->rate_control);
+       }
         ff_rtsp_send_cmd(s, "PLAY", rt->control_uri, cmd, reply, NULL);
         if (reply->status_code != RTSP_STATUS_OK) {
             return ff_rtsp_averror(reply->status_code, -1);
diff --git a/libavformat/rtspenc.c b/libavformat/rtspenc.c
index d50544456d..1b7281cc67 100644
--- a/libavformat/rtspenc.c
+++ b/libavformat/rtspenc.c
@@ -113,8 +113,13 @@ static int rtsp_write_record(AVFormatContext *s)
     RTSPMessageHeader reply1, *reply = &reply1;
     char cmd[1024];
 
-    snprintf(cmd, sizeof(cmd),
-             "Range: npt=0.000-\r\n");
+    if (rt->range != NULL) {
+        snprintf(cmd, sizeof(cmd),
+                 "Range: %s\r\n", rt->range);
+    } else {
+        snprintf(cmd, sizeof(cmd),
+                 "Range: npt=0.0000-\r\n");
+    }
     ff_rtsp_send_cmd(s, "RECORD", rt->control_uri, cmd, reply, NULL);
     if (reply->status_code != RTSP_STATUS_OK)
         return ff_rtsp_averror(reply->status_code, -1);
-- 
2.25.1