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

[Vladimir Voroshilov]

2009/6/18 Michael Niedermayer <michaelni at gmx.at>:
> On Thu, Jun 18, 2009 at 08:26:56AM +0700, Vladimir Voroshilov wrote:
>> 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)?
>
> its better, still the 2 line function that is used once remains and
> as said it should be inlined

I misunderstood you about inlining. Now fixed.

>
> [...]
>> @@ -124,6 +192,23 @@ static av_cold int decoder_init(AVCodecContext * avctx)
>> ? ? ?/* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
>> ? ? ?avctx->frame_size = SUBFRAME_SIZE << 1;
>>
>> + ? ?for (k = 0; k < MA_NP + 1; k++) {
>
>> + ? ? ? ?ctx->past_quantizer_outputs[k] = av_malloc(10 * sizeof(int16_t));
>
> this is unacceptable
> put the array in the struct, not allocate 20byte pieces with malloc

Is attached acceptable?
Or can it be improved  somehow?


>
> [...]
> --
> Michael ? ? GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> In fact, the RIAA has been known to suggest that students drop out
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> settlements. -- The RIAA
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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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