[FFmpeg-devel] [PATCH] adpcm: convert VLAs to malloc/free

[Loren Merritt]

On Sat, 26 Jun 2010, M?ns Rullg?rd wrote:

> static void adpcm_compress_trellis(AVCodecContext *avctx, const short *samples,
>                                    uint8_t *dst, ADPCMChannelStatus *c, int n)
> {
>-#define FREEZE_INTERVAL 128
>     //FIXME 6% faster if frontier is a compile-time constant
>+    ADPCMContext *s = avctx->priv_data;
>     const int frontier = 1 << avctx->trellis;
>     const int stride = avctx->channels;
>     const int version = avctx->codec->id;
>-    const int max_paths = frontier*FREEZE_INTERVAL;
>-    TrellisPath paths[max_paths], *p;
>-    TrellisNode node_buf[2][frontier];
>-    TrellisNode *nodep_buf[2][frontier];
>-    TrellisNode **nodes = nodep_buf[0]; // nodes[] is always sorted by .ssd
>-    TrellisNode **nodes_next = nodep_buf[1];
>+    TrellisPath *paths = s->paths, *p;
>+    TrellisNode *node_buf = s->node_buf;
>+    TrellisNode **nodep_buf = s->nodep_buf;
>+    TrellisNode **nodes = nodep_buf; // nodes[] is always sorted by .ssd
>+    TrellisNode **nodes_next = nodep_buf + frontier;
>     int pathn = 0, froze = -1, i, j, k;
>
>     assert(!(max_paths&(max_paths-1)));

max_paths no longer exists

Other than that, ok. I don't have any better ideas.

--Loren Merritt