[FFmpeg-devel] [HACK] Remove MAX_STREAMS usages

[Aurelien Jacobs]

On Fri, Sep 03, 2010 at 10:31:40AM +0200, Michael Niedermayer wrote:
> On Thu, Aug 12, 2010 at 10:13:20PM +0200, Aurelien Jacobs wrote:
> > On Wed, Aug 11, 2010 at 02:41:49PM -0700, Baptiste Coudurier wrote:
> > > Hi guys,
> > > 
> > > On 8/11/10 8:28 AM, Aurelien Jacobs wrote:
> > > >max_stream.diff
> > > >
> > > >
> > > >commit eb4a2bfc996713e70f60b556ed776cae3ab1cc5b
> > > >Author: Aurelien Jacobs<aurel at gnuage.org>
> > > >Date:   Tue Aug 10 00:21:06 2010 +0200
> > > >
> > > >     dynamically use nb_streams instead of static use of MAX_STREAMS
> > > >
> > > >diff --git a/libavformat/utils.c b/libavformat/utils.c
> > > >index 1aa965c..10e817d 100644
> > > >--- a/libavformat/utils.c
> > > >+++ b/libavformat/utils.c
> > > > [...]
> > > >@@ -2160,15 +2164,34 @@ int av_find_stream_info(AVFormatContext *ic)
> > > >      int i, count, ret, read_size, j;
> > > >      AVStream *st;
> > > >      AVPacket pkt1, *pkt;
> > > >-    int64_t last_dts[MAX_STREAMS];
> > > >-    int64_t duration_gcd[MAX_STREAMS]={0};
> > > >-    int duration_count[MAX_STREAMS]={0};
> > > >-    double (*duration_error)[MAX_STD_TIMEBASES];
> > > >+    int64_t *last_dts = NULL;
> > > >+    int64_t *duration_gcd = NULL;
> > > >+    int *duration_count = NULL;
> > > >+    double (*duration_error)[MAX_STD_TIMEBASES] = NULL;
> > > >      int64_t old_offset = url_ftell(ic->pb);
> > > >-    int64_t codec_info_duration[MAX_STREAMS]={0};
> > > >+    int64_t *codec_info_duration = NULL;
> > > >+    int nb_streams = 0;
> > > >+    void *tmp;
> > > >
> > > >-    duration_error = av_mallocz(MAX_STREAMS * sizeof(*duration_error));
> > > >-    if (!duration_error) return AVERROR(ENOMEM);
> > > >+#define GROW_BUFFER(buf, old_size, new_size)                           \
> > > >+    if (!(tmp = av_realloc(buf, new_size * sizeof(*buf)))) {           \
> > > >+        ret = AVERROR(ENOMEM);                                         \
> > > >+        goto err_out;                                                  \
> > > >+    }                                                                  \
> > > >+    buf = tmp;                                                         \
> > > >+    memset(buf+old_size, 0, (new_size-old_size) * sizeof(*buf));       \
> > > >+
> > > >+#define GROW_BUFFERS()                                                 \
> > > >+    if (ic->nb_streams>  nb_streams) {                                 \
> > > >+        GROW_BUFFER(last_dts,            nb_streams, ic->nb_streams);  \
> > > >+        GROW_BUFFER(duration_gcd,        nb_streams, ic->nb_streams);  \
> > > >+        GROW_BUFFER(duration_count,      nb_streams, ic->nb_streams);  \
> > > >+        GROW_BUFFER(duration_error,      nb_streams, ic->nb_streams);  \
> > > >+        GROW_BUFFER(codec_info_duration, nb_streams, ic->nb_streams);  \
> > > >+    }                                                                  \
> > > 
> > > I suggest to define a struct per stream to simplify the code.
> > 
> > I thought about this too... And then I discarded the idea. I don't
> > remember exactly why, but I guess I was just too lazy to change all
> > usage of those vars...
> > Anyway, I did it now. And it indeed looks a bit cleaner.
> > I split this into 2 patches. First one moves those vars into a struct,
> > and second one replace MAX_STREAMS usage by dynamic allocation.
> > 
> > Aurel
> >  utils.c |   60 ++++++++++++++++++++++++++++--------------------------------
> >  1 file changed, 28 insertions(+), 32 deletions(-)
> > a5229b9380dc8439a65b43a92be6b442658230ed  stream_info_array.diff
> > commit 3604eda5ff964b98cde9585890a7e265eb5a1fa8
> > Author: Aurelien Jacobs <aurel at gnuage.org>
> > Date:   Thu Aug 12 12:45:00 2010 +0200
> > 
> >     move stream info arrays into a struct to ease future dynamic allocation
> 
> ok

This part applied.
I will look at the other one later.

Aurel