[FFmpeg-devel] Add RTSP range header

[Andriy Gelman]

Hi,

On Sun, 22. Nov 11:21, 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.

When fetching the stream, have you tried to use -ss for seeking?  

Is the rate-control option only supported by the onvif cameras?
https://www.onvif.org/specs/stream/ONVIF-Streaming-Spec.pdf

If you want to add both options, they should be separate patches. And
you'll need to add documentation in doc/protocols.texi

> 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 },

I don't think you meant LIBAVFORMAT_IDENT to be the default (same for rate_control).                                                    
This would break seeking for regular streams.

> +    { "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);
> +       }

Your rate-control header is just going to overwrite your range header.

>          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);

-- 
Andriy