[FFmpeg-cvslog] r22974 - trunk/libavcodec/iff.c

[Michael Niedermayer]

On Tue, Apr 27, 2010 at 12:37:13AM +0200, rbultje wrote:
> Author: rbultje
> Date: Tue Apr 27 00:37:13 2010
> New Revision: 22974
> 
> Log:
> Switch some ints to unsigned (they can only have positive values, this allows
> compiler to optimize some math from mul/div to shr/shl). 


> Also add a cast to
> uint32_t when calling decodeplane32().

and why?


and who approved this patch?

review below:

[...]
> @@ -31,7 +32,7 @@
>  
>  typedef struct {
>      AVFrame frame;
> -    int planesize;
> +    unsigned planesize;

never used in >> or /


>      uint8_t * planebuf;
>  } IffContext;
>  
> @@ -40,7 +41,7 @@ typedef struct {
>   */
>  int ff_cmap_read_palette(AVCodecContext *avctx, uint32_t *pal)
>  {
> -    int count, i;
> +    unsigned count, i;

never used in >> or /
other variables not checked but i suspect these arent the only ones


>  
>      if (avctx->bits_per_coded_sample > 8) {
>          av_log(avctx, AV_LOG_ERROR, "bit_per_coded_sample > 8 not supported\n");
> @@ -71,7 +72,7 @@ static av_cold int decode_init(AVCodecCo
>          return AVERROR_INVALIDDATA;
>      }
>  
> -    s->planesize = avctx->width / 8;
> +    s->planesize = avctx->width >> 3;
>      s->planebuf = av_malloc(s->planesize + FF_INPUT_BUFFER_PADDING_SIZE);
>      if (!s->planebuf)
>          return AVERROR(ENOMEM);
> @@ -97,12 +98,11 @@ static av_cold int decode_init(AVCodecCo
>  static void decodeplane8(uint8_t *dst, const uint8_t *const buf, int buf_size, int bps, int plane)
>  {
>      GetBitContext gb;
> -    int i, b;
> +    unsigned int i;
> +    const unsigned b = (buf_size * 8) + bps - 1;
>      init_get_bits(&gb, buf, buf_size * 8);
> -    for(i = 0; i < (buf_size * 8 + bps - 1) / bps; i++) {
> -        for (b = 0; b < bps; b++) {
> -            dst[ i*bps + b ] |= get_bits1(&gb) << plane;
> -        }
> +    for(i = 0; i < b; i++) {
> +        dst[i] |= get_bits1(&gb) << plane;
>      }
>  }

unrelated change


>  
> @@ -117,12 +117,11 @@ static void decodeplane8(uint8_t *dst, c
>  static void decodeplane32(uint32_t *dst, const uint8_t *const buf, int buf_size, int bps, int plane)
>  {
>      GetBitContext gb;
> -    int i, b;
> +    unsigned i;
> +    const unsigned b = (buf_size * 8) + bps - 1;
>      init_get_bits(&gb, buf, buf_size * 8);
> -    for(i = 0; i < (buf_size * 8 + bps - 1) / bps; i++) {
> -        for (b = 0; b < bps; b++) {
> -            dst[ i*bps + b ] |= get_bits1(&gb) << plane;
> -        }
> +    for(i = 0; i < b; i++) {
> +        dst[i] |= get_bits1(&gb) << plane;
>      }
>  }

same


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

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates
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