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

Ross Nicholson phunkyfish at gmail.com
Wed Apr 15 19:21:06 EEST 2020


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
>>> >> _______________________________________________
>>> >> ffmpeg-devel mailing list
>>> >> ffmpeg-devel at ffmpeg.org
>>> >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> >> 
>>> >> To unsubscribe, visit link above, or email
>>> >> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>>> > _______________________________________________
>>> > ffmpeg-devel mailing list
>>> > ffmpeg-devel at ffmpeg.org
>>> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> >
>>> > To unsubscribe, visit link above, or email
>>> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel at ffmpeg.org
>>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> 
>>> To unsubscribe, visit link above, or email
>>> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".


More information about the ffmpeg-devel mailing list