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dca: allocate a secondary buffer for extra channels when downmixing

The output AVFrame buffer only has data for the downmix channels.
Fixes a segfault when decoding dca with request_channels == 2.
This commit is contained in:
Justin Ruggles 2012-10-11 14:21:56 -04:00
parent a77f01c725
commit 61d5313d94

View File

@ -32,6 +32,7 @@
#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "libavutil/audioconvert.h"
#include "libavutil/samplefmt.h"
#include "avcodec.h"
#include "dsputil.h"
#include "fft.h"
@ -357,6 +358,9 @@ typedef struct {
DECLARE_ALIGNED(32, float, subband_samples)[DCA_BLOCKS_MAX][DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][8];
float *samples_chanptr[DCA_PRIM_CHANNELS_MAX + 1];
float *extra_channels[DCA_PRIM_CHANNELS_MAX + 1];
uint8_t *extra_channels_buffer;
unsigned int extra_channels_buffer_size;
uint8_t dca_buffer[DCA_MAX_FRAME_SIZE + DCA_MAX_EXSS_HEADER_SIZE + DCA_BUFFER_PADDING_SIZE];
int dca_buffer_size; ///< how much data is in the dca_buffer
@ -1656,7 +1660,7 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
int i, ret;
float **samples_flt;
DCAContext *s = avctx->priv_data;
int channels;
int channels, full_channels;
int core_ss_end;
@ -1790,7 +1794,7 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
avctx->profile = s->profile;
channels = s->prim_channels + !!s->lfe;
full_channels = channels = s->prim_channels + !!s->lfe;
if (s->amode < 16) {
avctx->channel_layout = dca_core_channel_layout[s->amode];
@ -1852,12 +1856,35 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
}
samples_flt = (float **) s->frame.extended_data;
/* allocate buffer for extra channels if downmixing */
if (avctx->channels < full_channels) {
ret = av_samples_get_buffer_size(NULL, full_channels - channels,
s->frame.nb_samples,
avctx->sample_fmt, 0);
if (ret < 0)
return ret;
av_fast_malloc(&s->extra_channels_buffer,
&s->extra_channels_buffer_size, ret);
if (!s->extra_channels_buffer)
return AVERROR(ENOMEM);
ret = av_samples_fill_arrays((uint8_t **)s->extra_channels, NULL,
s->extra_channels_buffer,
full_channels - channels,
s->frame.nb_samples, avctx->sample_fmt, 0);
if (ret < 0)
return ret;
}
/* filter to get final output */
for (i = 0; i < (s->sample_blocks / 8); i++) {
int ch;
for (ch = 0; ch < channels; ch++)
s->samples_chanptr[ch] = samples_flt[ch] + i * 256;
for (; ch < full_channels; ch++)
s->samples_chanptr[ch] = s->extra_channels[ch - channels] + i * 256;
dca_filter_channels(s, i);
@ -1922,6 +1949,7 @@ static av_cold int dca_decode_end(AVCodecContext *avctx)
{
DCAContext *s = avctx->priv_data;
ff_mdct_end(&s->imdct);
av_freep(&s->extra_channels_buffer);
return 0;
}