[FFmpeg-devel] [PATCH] G.729 LSF decoding

[Vladimir Voroshilov]

2009/6/18 Michael Niedermayer <michaelni at gmx.at>:
> On Thu, Jun 18, 2009 at 02:10:52AM +0700, Vladimir Voroshilov wrote:
>> 2009/6/18 Diego Biurrun <diego at biurrun.de>:
>> > On Thu, Jun 18, 2009 at 02:00:37AM +0700, Vladimir Voroshilov wrote:
>> >> First patch for main decoding routine.
>> >> Decodes LSF (Linear Spectrum Frequencies, if i'm not wrong).
>> >>
>> >> --- ffmpeg-r19188/libavcodec/g729dec.c
>> >> +++ ffmpeg-r19188_v153/libavcodec/g729dec.c
>> >> @@ -114,8 +119,74 @@ static inline int get_parity(uint8_t value)
>> >>
>> >> + ? ?/* Rotate past_quantizer_outputs. */
>> >> + ? ?for(k=MA_NP-1; k>0; k--)
>> >
>> > nit: inconsistently formatted for construct
>>
>> Damn. One was overlooked...
>> Fixed.
>>
>
> [...]
>> @@ -114,8 +119,74 @@ static inline int get_parity(uint8_t value)
>> ? ? return (0x6996966996696996ULL >> (value >> 2)) & 1;
>> ?}
>>
>> +/**
>> + * Saves quantized LSF coefficients for use in next frame.
>> + * @param past_quantizer_outputs [in/out] (2.13) quantizer outputs from previous frames
>> + * @param quantizer_output (2.13) current quantizer output
>> + */
>> +static void lq_rotate(int16_t past_quantizer_outputs[MA_NP][10],
>> + ? ? ? ? ? ? ? ? ? ? ?const int16_t* quantizer_output)
>> +{
>> + ? ?int k;
>> +
>> + ? ?/* Rotate past_quantizer_outputs. */
>> + ? ?for (k = MA_NP - 1; k > 0; k--)
>> + ? ? ? ?memcpy(past_quantizer_outputs[k], past_quantizer_outputs[k-1], 10 * sizeof(int16_t));
>> + ? ?memcpy(past_quantizer_outputs[0], quantizer_output, 10 * sizeof(int16_t));
>> +}
>
> used just once and 3 lines, must be inlined
>
> note: memcpy() will not be approved before the neccessarity is clear

Replaced several memcpy with pointer rotation via memmove.
Is such fix enough (patch attached)?
should i also replace quantizer_outputs with
past_quantizer_outputs[MA_NP] everywhere
(instead of current assignment) and also remove second parameter in lq_rotate ?

>
>
> [...]
> --
> Michael ? ? GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> If a bugfix only changes things apparently unrelated to the bug with no
> further explanation, that is a good sign that the bugfix is wrong.
>
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-- 
Regards,
Vladimir Voroshilov     mailto:voroshil at gmail.com
JID: voroshil at gmail.com, voroshil at jabber.ru
ICQ: 95587719
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