[FFmpeg-devel] [PATCH] aacenc: replace VLA with malloced buffer in context

[Alex Converse]

On Sat, Jul 3, 2010 at 8:59 PM, Mans Rullgard <mans at mansr.com> wrote:
> ---
> ?libavcodec/aacenc.c | ? ?6 +++++-
> ?libavcodec/aacenc.h | ? ?1 +
> ?2 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/libavcodec/aacenc.c b/libavcodec/aacenc.c
> index 1aaaf3a..78eb7d2 100644
> --- a/libavcodec/aacenc.c
> +++ b/libavcodec/aacenc.c
> @@ -202,6 +202,9 @@ static av_cold int aac_encode_init(AVCodecContext *avctx)
> ? ? ff_psy_init(&s->psy, avctx, 2, sizes, lengths);
> ? ? s->psypp = ff_psy_preprocess_init(avctx);
> ? ? s->coder = &ff_aac_coders[2];
> + ? ?s->psywindows = av_malloc(avctx->channels * sizeof(*s->psywindows));
> + ? ?if (!s->psywindows)
> + ? ? ? ?return AVERROR(ENOMEM);
>
> ? ? s->lambda = avctx->global_quality ? avctx->global_quality : 120;
>
> @@ -486,7 +489,7 @@ static int aac_encode_frame(AVCodecContext *avctx,
> ? ? int i, j, chans, tag, start_ch;
> ? ? const uint8_t *chan_map = aac_chan_configs[avctx->channels-1];
> ? ? int chan_el_counter[4];
> - ? ?FFPsyWindowInfo windows[avctx->channels];
> + ? ?FFPsyWindowInfo *windows = s->psywindows;
>
> ? ? if (s->last_frame)
> ? ? ? ? return 0;
> @@ -625,6 +628,7 @@ static av_cold int aac_encode_end(AVCodecContext *avctx)
> ? ? ff_mdct_end(&s->mdct128);
> ? ? ff_psy_end(&s->psy);
> ? ? ff_psy_preprocess_end(s->psypp);
> + ? ?av_freep(&s->psywindows);
> ? ? av_freep(&s->samples);
> ? ? av_freep(&s->cpe);
> ? ? return 0;
> diff --git a/libavcodec/aacenc.h b/libavcodec/aacenc.h
> index 86c68d3..1f730c0 100644
> --- a/libavcodec/aacenc.h
> +++ b/libavcodec/aacenc.h
> @@ -60,6 +60,7 @@ typedef struct AACEncContext {
> ? ? ChannelElement *cpe; ? ? ? ? ? ? ? ? ? ? ? ? ///< channel elements
> ? ? FFPsyContext psy;
> ? ? struct FFPsyPreprocessContext* psypp;
> + ? ?FFPsyWindowInfo *psywindows;
> ? ? AACCoefficientsEncoder *coder;
> ? ? int cur_channel;
> ? ? int last_frame;
> --

Is there a reason you didn't just make this fixed sized on the stack?

aacenc only supports 6 channels.

 169     if (avctx->channels > 6) {
 170         av_log(avctx, AV_LOG_ERROR, "Unsupported number of
channels: %d\n", avctx->channels);
 171         return -1;
 172     }

--Alex