[alsa-devel] [PATCH] speaker-test.c - fix sine generator on big-endian archs

[Takashi Iwai]

At Sat, 19 Apr 2008 23:50:08 +0200,
Giuliano Pochini wrote:
> 
> speaker-test doesn't work well when you choose a little-endian format on a
> big-endian processor, or the opposite. Yes, I know about plughw:, but for
> debugging purposes it may not be an option. The following patch add proper
> support for S32 and S16 support for but LE and BE processors:
> 
> - The "if (bits-per-sample)" construct was replaced by case (format).
> - Support for S16_BE, S32_BE formats was added.
> - S16_LE and S32_LE were made compatible with big-endian processors.
> - NB: The pink noise generator wasn't changed (I'll do if this patch is OK).

Looks simple enough.  Applied to HG tree now.


Thanks,

Takashi


> 
> 
> --- speaker-test/speaker-test.c__orig	2008-04-19 23:01:22.000000000 +0200
> +++ speaker-test/speaker-test.c	2008-04-19 23:29:45.000000000 +0200
> @@ -139,7 +139,6 @@ static void generate_sine(uint8_t *frame
>    int16_t *samp16 = (int16_t*) frames;
>    int32_t *samp32 = (int32_t*) frames;
>    float   *samp_f = (float*) frames;
> -  int sample_size_bits = snd_pcm_format_width(format); 
>  
>    while (count-- > 0) {
>      //res = sin((phase * 2 * M_PI) / max_phase - M_PI) * 32767;
> @@ -154,26 +153,43 @@ static void generate_sine(uint8_t *frame
>      //ires = 0;
>  
>      for(chn=0;chn<channels;chn++) {
> -      if (sample_size_bits == 8) {
> +      switch (format) {
> +      case SND_PCM_FORMAT_S8:
>          if (chn==channel) {
>            res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0x03fffffff; /* Don't use MAX volume */
>            ires = res;
> -	  *samp8++ = ires >> 24;
> -	  //*samp8++ = 0x12;
> +          *samp8++ = ires >> 24;
>          } else {
> -	  *samp8++ = 0;
> +          *samp8++ = 0;
>          }
> -      } else if (sample_size_bits == 16) {
> +        break;
> +      case SND_PCM_FORMAT_S16_LE:
>          if (chn==channel) {
>            res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0x03fffffff; /* Don't use MAX volume */
>            ires = res;
> -	  *samp16++ = ires >>16;
> -	  //*samp16++ = 0x1234;
> +#if __BYTE_ORDER == __LITTLE_ENDIAN
> +          *samp16++ = ires >> 16;
> +#elif __BYTE_ORDER == __BIG_ENDIAN
> +          *samp16++ = bswap_16(ires >> 16);
> +#endif
>          } else {
> -	  //*samp16++ = (ires >>16)+1;
> -	  *samp16++ = 0;
> +          *samp16++ = 0;
>          }
> -      } else if ((sample_size_bits == 32) && (format == SND_PCM_FORMAT_FLOAT_LE)) {
> +        break;
> +      case SND_PCM_FORMAT_S16_BE:
> +        if (chn==channel) {
> +          res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0x03fffffff; /* Don't use MAX volume */
> +          ires = res;
> +#if __BYTE_ORDER == __BIG_ENDIAN
> +          *samp16++ = ires >> 16;
> +#elif __BYTE_ORDER == __LITTLE_ENDIAN
> +          *samp16++ = bswap_16(ires >> 16);
> +#endif
> +        } else {
> +          *samp16++ = 0;
> +        }
> +        break;
> +      case SND_PCM_FORMAT_FLOAT_LE:
>          if (chn==channel) {
>            res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0.75 ; /* Don't use MAX volume */
>            fres = res;
> @@ -185,18 +201,35 @@ static void generate_sine(uint8_t *frame
>  	  //*samp32++ = ires;
>  	  *samp_f++ = 0.0;
>          }
> -      } else if ((sample_size_bits == 32) && (format != SND_PCM_FORMAT_FLOAT_LE)) {
> +        break;
> +      case SND_PCM_FORMAT_S32_LE:
>          if (chn==channel) {
>            res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0x03fffffff; /* Don't use MAX volume */
>            ires = res;
> -	  *samp32++ = ires;
> -	  //*samp32++ = 0xF2345678;
> -	//printf("res=%lf, ires=%d 0x%x, samp32=0x%x\n",res,ires, ires, samp32[-1]);
> +#if __BYTE_ORDER == __LITTLE_ENDIAN
> +          *samp32++ = ires;
> +#elif __BYTE_ORDER == __BIG_ENDIAN
> +          *samp32++ = bswap_32(ires);
> +#endif
>          } else {
> -	  //*samp32++ = ires+0x10000;
> -	  //*samp32++ = ires;
> -	  *samp32++ = 0;
> +          *samp32++ = 0;
>          }
> +        break;
> +      case SND_PCM_FORMAT_S32_BE:
> +        if (chn==channel) {
> +          res = (sin((phase * 2 * M_PI) / max_phase - M_PI)) * 0x03fffffff; /* Don't use MAX volume */
> +          ires = res;
> +#if __BYTE_ORDER == __BIG_ENDIAN
> +          *samp32++ = ires;
> +#elif __BYTE_ORDER == __LITTLE_ENDIAN
> +          *samp32++ = bswap_32(ires);
> +#endif
> +        } else {
> +          *samp32++ = 0;
> +        }
> +        break;
> +      default:
> +        ;
>        }
>      }
>  
> 
> --
> Giuliano.
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