[FFmpeg-devel] [PATCH] avformat/rtp: Pass sources and block filter addresses via sdp file for rtp

Ross Nicholson phunkyfish at gmail.com
Fri Apr 17 14:07:14 EEST 2020


Ping

> On 15 Apr 2020, at 17:21, Ross Nicholson <phunkyfish at gmail.com> wrote:
> 
> 
> Ping to hopefully apply this patch!
> 
>>> On 12 Apr 2020, at 16:54, Ross Nicholson <phunkyfish at gmail.com> wrote:
>>> 
>> 
>> User testing has been completed successfully so this is ready to be applied.
>> 
>> Thanks 
>> 
>>>> On 7 Apr 2020, at 23:50, Ross Nicholson <phunkyfish at gmail.com> wrote:
>>>> 
>>> 
>>> Thank you for the explanation Marton. It's make perfect sense to me know. So UNLIMITED would be the right choice here.
>>> 
>>> All of your other comments are addressed in the latest version. Thanks again for reviewing.
>>> 
>>>> On Tue, 7 Apr 2020 at 22:03, Marton Balint <cus at passwd.hu> wrote:
>>>> 
>>>> 
>>>> On Tue, 7 Apr 2020, Ross Nicholson wrote:
>>>> 
>>>> > Great, thanks again. 
>>>> >
>>>> > A question about AV_BPRINT_SIZE_AUTOMATIC. Is there a heuristic for when to use this versus unlimited?
>>>> >
>>>> > Or is it that generally if you would have used a buffer of 1000 or less automatic is the right choice?
>>>> 
>>>> It depends on what you want. With AUTOMATIC you limit length to 1000 chars 
>>>> but you don't have to free the buffer. Otherwise you are not limiting the 
>>>> buffer size, but you have to free it. So if it is impossible to hit the 
>>>> limit, you should always use AUTOMATIC.
>>>> 
>>>> In this case you have to decide for yourself which to use, because I don't 
>>>> know if 1000 char buffer is big enough for the possible use cases. I 
>>>> only suggested to consider it, because you are using limited buffers for 
>>>> other strings, so it may not even be possible to outgrow 1000 chars. It is 
>>>> up to you decide depending on what you want to support.
>>>> 
>>>> Regards,
>>>> Marton
>>>> 
>>>> >
>>>> >> On 7 Apr 2020, at 20:50, Marton Balint <cus at passwd.hu> wrote:
>>>> >> 
>>>> >> 
>>>> >> 
>>>> >>> On Tue, 7 Apr 2020, phunkyfish wrote:
>>>> >>> 
>>>> >>> ---
>>>> >>> libavformat/rtsp.c | 48 +++++++++++++++++++++++++++++++++++++---------
>>>> >>> 1 file changed, 39 insertions(+), 9 deletions(-)
>>>> >>> 
>>>> >>> diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
>>>> >>> index cd6fc32a29..dad3f7915e 100644
>>>> >>> --- a/libavformat/rtsp.c
>>>> >>> +++ b/libavformat/rtsp.c
>>>> >>> @@ -21,6 +21,7 @@
>>>> >>> #include "libavutil/avassert.h"
>>>> >>> #include "libavutil/base64.h"
>>>> >>> +#include "libavutil/bprint.h"
>>>> >>> #include "libavutil/avstring.h"
>>>> >>> #include "libavutil/intreadwrite.h"
>>>> >>> #include "libavutil/mathematics.h"
>>>> >>> @@ -2447,7 +2448,7 @@ static int rtp_probe(const AVProbeData *p)
>>>> >>> static int rtp_read_header(AVFormatContext *s)
>>>> >>> {
>>>> >>>    uint8_t recvbuf[RTP_MAX_PACKET_LENGTH];
>>>> >>> -    char host[500], sdp[500];
>>>> >>> +    char host[500], filters_buf[1000];
>>>> >>>    int ret, port;
>>>> >>>    URLContext* in = NULL;
>>>> >>>    int payload_type;
>>>> >>> @@ -2456,6 +2457,8 @@ static int rtp_read_header(AVFormatContext *s)
>>>> >>>    AVIOContext pb;
>>>> >>>    socklen_t addrlen = sizeof(addr);
>>>> >>>    RTSPState *rt = s->priv_data;
>>>> >>> +    const char *p;
>>>> >>> +    AVBPrint sdp;
>>>> >>>
>>>> >>>    if (!ff_network_init())
>>>> >>>        return AVERROR(EIO);
>>>> >>> @@ -2513,16 +2516,38 @@ static int rtp_read_header(AVFormatContext *s)
>>>> >>>    av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port,
>>>> >>>                 NULL, 0, s->url);
>>>> >>> -    snprintf(sdp, sizeof(sdp),
>>>> >>> -             "v=0\r\nc=IN IP%d %s\r\nm=%s %d RTP/AVP %d\r\n",
>>>> >>> -             addr.ss_family == AF_INET ? 4 : 6, host,
>>>> >>> -             par->codec_type == AVMEDIA_TYPE_DATA  ? "application" :
>>>> >>> -             par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio",
>>>> >>> -             port, payload_type);
>>>> >>> -    av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sdp);
>>>> >>> +    av_bprint_init(&sdp, 0, AV_BPRINT_SIZE_UNLIMITED);
>>>> >> 
>>>> >> You may also use AV_BPRINT_SIZE_AUTOMATIC in which case you will get a static buffer which will be limited (roughly 1000 chars) but you don't have to free it with av_bprint_finalize().
>>>> >> 
>>>> >>> +    av_bprintf(&sdp, "v=0\r\nc=IN IP%d %s\r\n",
>>>> >>> +               addr.ss_family == AF_INET ? 4 : 6, host);
>>>> >>> +
>>>> >>> +    p = strchr(s->url, '?');
>>>> >>> +    if (p) {
>>>> >>> +        static const char *filters[][2] = {{"sources", "incl"}, {"block", "excl"}, {NULL, NULL}};
>>>> >>> +        int i;
>>>> >>> +        char *q;
>>>> >>> +        for (i = 0; filters[i][0]; i++) {
>>>> >>> +            if (av_find_info_tag(filters_buf, sizeof(filters_buf), filters[i][0], p)) {
>>>> >>> +                q = filters_buf;
>>>> >>> +                while ((q = strchr(q, ',')) != NULL)
>>>> >>> +                    *q = ' ';
>>>> >>> +                av_bprintf(&sdp, "a=source-filter:%s IN IP%d %s %s\r\n",
>>>> >>> +                           filters[i][1],
>>>> >>> +                           addr.ss_family == AF_INET ? 4 : 6, host,
>>>> >>> +                           filters_buf);
>>>> >>> +            }
>>>> >>> +        }
>>>> >>> +    }
>>>> >>> +
>>>> >>> +    av_bprintf(&sdp, "m=%s %d RTP/AVP %d\r\n",
>>>> >>> +               par->codec_type == AVMEDIA_TYPE_DATA  ? "application" :
>>>> >>> +               par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio",
>>>> >>> +               port, payload_type);
>>>> >>> +    av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sdp.str);
>>>> >>> +    if (av_bprint_is_complete(&sdp))
>>>> >> 
>>>> >> I think this check should be negated here, because you want to report error if the buffer is truncated, not if it is complete.
>>>> >> 
>>>> >>> +        goto fail_nobuf;
>>>> >>>    avcodec_parameters_free(&par);
>>>> >>> -    ffio_init_context(&pb, sdp, strlen(sdp), 0, NULL, NULL, NULL, NULL);
>>>> >>> +    ffio_init_context(&pb, sdp.str, strlen(sdp.str), 0, NULL, NULL, NULL, NULL);
>>>> >> 
>>>> >> You can use sdp.len instead of strlen().
>>>> >>
>>>> >>>    s->pb = &pb;
>>>> >>>
>>>> >>>    /* sdp_read_header initializes this again */
>>>> >>> @@ -2532,9 +2557,14 @@ static int rtp_read_header(AVFormatContext *s)
>>>> >>>
>>>> >>>    ret = sdp_read_header(s);
>>>> >>>    s->pb = NULL;
>>>> >>> +    av_bprint_finalize(&sdp, NULL);
>>>> >>>    return ret;
>>>> >>> +fail_nobuf:
>>>> >>> +    ret = AVERROR(ENOMEM);
>>>> >>> +    av_log(s, AV_LOG_ERROR, "rtp_read_header(): not enough buffer space for sdp-headers\n");
>>>> >>> fail:
>>>> >>> +    av_bprint_finalize(&sdp, NULL);
>>>> >>>    avcodec_parameters_free(&par);
>>>> >>>    if (in)
>>>> >>>        ffurl_close(in);
>>>> >> 
>>>> >> Regards,
>>>> >> Marton
>>>> >> _______________________________________________
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>>>> >> 
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