[FFmpeg-devel] [PATCH] mxfdec: make it work with other calling conventions

[Baptiste Coudurier]

On 6/29/10 11:51 AM, Reimar D?ffinger wrote:
> On Tue, Jun 29, 2010 at 08:30:01PM +0200, Reimar D?ffinger wrote:
>> Hello,
>> currently mxfdec assumes that it can unpunished pass more arguments to functions
>> than they were declared with.
>> This is not true in general, in particular not for stdcall.
>> While I am not aware of any FFmpeg platform using it, IMHO this code is still
>> wrong.
>> Attached is a patch that fixes it, and I think it is not particularly bad.
>> It also fixes the last remaining warnings ("function declaration is not a prototype")
>> in that file.

I don't have this warning.
gcc version 4.4.4 (Ubuntu 4.4.4-6ubuntu2)

> Now actually working (had a break instead of a continue there in one place)...
>
>
> mxfdec.diff
>
>
> Index: libavformat/mxfdec.c
> ===================================================================
> --- libavformat/mxfdec.c	(revision 23891)
> +++ libavformat/mxfdec.c	(working copy)
> @@ -139,9 +139,12 @@
>       Clip,
>   };
>
> +#define METADATA_READ_FUNC(name) int name(void *arg, ByteIOContext *pb, int tag, int size, UID uid)

I don't like the #define.

 > [...]
>
> @@ -919,11 +931,14 @@
>               url_fseek(s->pb, klv.offset, SEEK_SET);
>               break;
>           }
> +        if (IS_KLV_KEY(klv.key, mxf_primer_pack_key)) {
> +            mxf_read_primer_pack(mxf);
> +            continue;
> +        }
>
>           for (metadata = mxf_metadata_read_table; metadata->read; metadata++) {
>               if (IS_KLV_KEY(klv.key, metadata->key)) {
> -                int (*read)() = klv.key[5] == 0x53 ? mxf_read_local_tags : metadata->read;
> -                if (read(mxf,&klv, metadata->read, metadata->ctx_size, metadata->type)<  0) {
> +                if (mxf_read_local_tags(mxf,&klv, metadata->read, metadata->ctx_size, metadata->type)<  0) {

This mechanism makes it easier to add new functions.
Several metadata use 0x53 and it is needed later.

-- 
Baptiste COUDURIER
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