[FFmpeg-devel] [PATCH] http: try to detect live akamai streams and dont enable seeking for them

[Michael Niedermayer]

On Mon, Jun 04, 2012 at 07:13:21PM +0200, Reimar Döffinger wrote:
> On Mon, Jun 04, 2012 at 03:14:20PM +0200, Michael Niedermayer wrote:
> > On Mon, Jun 04, 2012 at 07:45:48AM +0200, Reimar Döffinger wrote:
> > > On 4 Jun 2012, at 02:28, Michael Niedermayer <michaelni at gmx.at> wrote:
> > > > On Mon, Jun 04, 2012 at 02:25:57AM +0200, Michael Niedermayer wrote:
> > > >> On Sun, Jun 03, 2012 at 10:38:14PM +0200, Reimar Döffinger wrote:
> > > >>> On Sun, Jun 03, 2012 at 06:43:33PM +0200, Clément Bœsch wrote:
> > > >>>> On Sun, Jun 03, 2012 at 06:36:34PM +0200, Michael Niedermayer wrote:
> > > >>>>> Fixes ticket1320
> > > >>>>> 
> > > >>>>> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> > > >>>>> ---
> > > >>>>> libavformat/http.c |    6 +++++-
> > > >>>>> 1 file changed, 5 insertions(+), 1 deletion(-)
> > > >>>>> 
> > > >>>>> diff --git a/libavformat/http.c b/libavformat/http.c
> > > >>>>> index 9a5ca62..28a777c 100644
> > > >>>>> --- a/libavformat/http.c
> > > >>>>> +++ b/libavformat/http.c
> > > >>>>> @@ -57,6 +57,7 @@ typedef struct {
> > > >>>>>     int multiple_requests;  /**< A flag which indicates if we use persistent connections. */
> > > >>>>>     uint8_t *post_data;
> > > >>>>>     int post_datalen;
> > > >>>>> +    int is_akamai;
> > > >>>>> } HTTPContext;
> > > >>>>> 
> > > >>>>> #define OFFSET(x) offsetof(HTTPContext, x)
> > > >>>>> @@ -318,7 +319,8 @@ static int process_line(URLContext *h, char *line, int line_count,
> > > >>>>>                 if ((slash = strchr(p, '/')) && strlen(slash) > 0)
> > > >>>>>                     s->filesize = atoll(slash+1);
> > > >>>>>             }
> > > >>>>> -            h->is_streamed = 0; /* we _can_ in fact seek */
> > > >>>>> +            if (!s->is_akamai || s->filesize != 2147483647)
> > > >>>>> +                h->is_streamed = 0; /* we _can_ in fact seek */
> > > >>>>>         } else if (!av_strcasecmp(tag, "Accept-Ranges") && !strncmp(p, "bytes", 5)) {
> > > >>>>>             h->is_streamed = 0;
> > > >>>>>         } else if (!av_strcasecmp (tag, "Transfer-Encoding") && !av_strncasecmp(p, "chunked", 7)) {
> > > >>>>> @@ -333,6 +335,8 @@ static int process_line(URLContext *h, char *line, int line_count,
> > > >>>>>         } else if (!av_strcasecmp (tag, "Connection")) {
> > > >>>>>             if (!strcmp(p, "close"))
> > > >>>>>                 s->willclose = 1;
> > > >>>>> +        } else if (!av_strcasecmp (tag, "Server") && !av_strcasecmp (p, "AkamaiGHost")) {
> > > >>>>> +            s->is_akamai = 1;
> > > >>>>>         }
> > > >>>>>     }
> > > >>>> 
> > > >>>> This reminds me of a similar issue Reimar fixed in MPlayer by adding
> > > >>>> another exception (IIRC it was Youtube); this might be a fairly common
> > > >>>> issue with some webservers, so maybe a more generic attribute could be
> > > >>>> used? (broken_httpserver or something).
> > > >>> 
> > > >>> I'm not sure if FFmpeg's http implementation can detect it in some other
> > > >>> way, however it is true that in MPlayer we have two other broken cases
> > > >>> (and we lack this one). YouTube and MakeMKV are those.
> > > >>> (see stream/http.c:758).
> > > >> 
> > > >> do you have testcases for the 2 ?
> > > >> so we can check if ffmpeg needs such checks too ?
> > > > 
> > > > s/we/i/
> > > 
> > > Not sure about YouTube, though I guess any video would have to do?
> > 
> > tried but it seems the flv stream contains no index and our http
> > doesnt support seeking by time
> > mplayer itself fails to seek as well
> > 
> > not sure if i did something wrong ...
> 
> I admit I don't remember the test-case. My first suggestion would be to
> try with the HTML5/webm versions of the videos if you haven't.

i didnt ...
webm works perfectly also doesnt need any changes to http.c
libavformat detects that its seekable


> Though I would have thought that the flv streams should have an index,
> otherwise how does flash player do seeking?

i dont know, someone should look at the http traffik between the flash
player and google
but maybe it just seeks by assuming CBR :)
or iam an idiot and miss something


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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