On 10/6/15, James Almer <jamr...@gmail.com> wrote:
> Since AVFrame.extended_data is apparently not padded, simd functions
> could in some cases overread, so make the decoder use a temp buffer
> unconditionally.
>
> Signed-off-by: James Almer <jamr...@gmail.com>
> ---
> libavcodec/alac.c | 18 +++++-------------
> 1 file changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/libavcodec/alac.c b/libavcodec/alac.c
> index 146668e..394bd19 100644
> --- a/libavcodec/alac.c
> +++ b/libavcodec/alac.c
> @@ -80,7 +80,6 @@ typedef struct ALACContext {
> int extra_bits; /**< number of extra bits beyond 16-bit */
> int nb_samples; /**< number of samples in the current frame */
>
> - int direct_output;
> int extra_bit_bug;
>
> ALACDSPContext dsp;
> @@ -278,10 +277,6 @@ static int decode_element(AVCodecContext *avctx,
> AVFrame *frame, int ch_index,
> return AVERROR_INVALIDDATA;
> }
> alac->nb_samples = output_samples;
> - if (alac->direct_output) {
> - for (ch = 0; ch < channels; ch++)
> - alac->output_samples_buffer[ch] = (int32_t
> *)frame->extended_data[ch_index + ch];
> - }
>
> if (is_compressed) {
> int16_t lpc_coefs[2][32];
> @@ -393,8 +388,9 @@ static int decode_element(AVCodecContext *avctx, AVFrame
> *frame, int ch_index,
> break;
> case 24: {
> for (ch = 0; ch < channels; ch++) {
> + int32_t *outbuffer = (int32_t *)frame->extended_data[ch_index +
> ch];
> for (i = 0; i < alac->nb_samples; i++)
> - alac->output_samples_buffer[ch][i] <<= 8;
> + *outbuffer++ = alac->output_samples_buffer[ch][i] << 8;
> }}
> break;
> }
> @@ -468,8 +464,7 @@ static av_cold int alac_decode_close(AVCodecContext
> *avctx)
> int ch;
> for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
> av_freep(&alac->predict_error_buffer[ch]);
> - if (!alac->direct_output)
> - av_freep(&alac->output_samples_buffer[ch]);
> + av_freep(&alac->output_samples_buffer[ch]);
> av_freep(&alac->extra_bits_buffer[ch]);
> }
>
> @@ -491,11 +486,8 @@ static int allocate_buffers(ALACContext *alac)
> FF_ALLOC_OR_GOTO(alac->avctx, alac->predict_error_buffer[ch],
> buf_size, buf_alloc_fail);
>
> - alac->direct_output = alac->sample_size > 16;
> - if (!alac->direct_output) {
> - FF_ALLOC_OR_GOTO(alac->avctx, alac->output_samples_buffer[ch],
> - buf_size, buf_alloc_fail);
> - }
> + FF_ALLOC_OR_GOTO(alac->avctx, alac->output_samples_buffer[ch],
> + buf_size, buf_alloc_fail);
>
> FF_ALLOC_OR_GOTO(alac->avctx, alac->extra_bits_buffer[ch],
> buf_size, buf_alloc_fail);
> --
> 2.5.2
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
it should be padded and not introduce slowdown
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