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libspeexdec: decode one frame at a time.

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This allows for knowing the output size before decoding even when there is no
header (e.g. FLV). Otherwise we would have to do a preliminary full frame
decode to determine the number of frames-per-packet.
This commit is contained in:
Justin Ruggles 2011-10-21 12:07:42 -04:00
parent 41ac093f7e
commit 7eeaa6796b
1 changed files with 35 additions and 17 deletions
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52
libavcodec/libspeexdec.c
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@ -99,32 +99,42 @@ static int libspeex_decode_frame(AVCodecContext *avctx,
uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
LibSpeexContext *s = avctx->priv_data;
int16_t *output = data, *end;
int i, num_samples;
int16_t *output = data;
int out_size, ret, consumed = 0;
num_samples = s->frame_size * avctx->channels;
end = output + *data_size / sizeof(*output);
/* check output buffer size */
out_size = s->frame_size * avctx->channels *
av_get_bytes_per_sample(avctx->sample_fmt);
if (*data_size < out_size) {
av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
return AVERROR(EINVAL);
}
speex_bits_read_from(&s->bits, buf, buf_size);
/* if there is not enough data left for the smallest possible frame,
reset the libspeex buffer using the current packet, otherwise ignore
the current packet and keep decoding frames from the libspeex buffer. */
if (speex_bits_remaining(&s->bits) < 43) {
/* check for flush packet */
if (!buf || !buf_size) {
*data_size = 0;
return buf_size;
}
/* set new buffer */
speex_bits_read_from(&s->bits, buf, buf_size);
consumed = buf_size;
}
for (i = 0; speex_bits_remaining(&s->bits) && output + num_samples < end; i++) {
int ret = speex_decode_int(s->dec_state, &s->bits, output);
/* decode a single frame */
ret = speex_decode_int(s->dec_state, &s->bits, output);
if (ret <= -2) {
av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
return -1;
} else if (ret == -1)
// end of stream
break;
}
if (avctx->channels == 2)
speex_decode_stereo_int(output, s->frame_size, &s->stereo);
output += num_samples;
}
avctx->frame_size = s->frame_size * i;
*data_size = avctx->channels * avctx->frame_size * sizeof(*output);
return buf_size;
*data_size = out_size;
return consumed;
}
static av_cold int libspeex_decode_close(AVCodecContext *avctx)
@ -138,6 +148,12 @@ static av_cold int libspeex_decode_close(AVCodecContext *avctx)
return 0;
}
static av_cold void libspeex_decode_flush(AVCodecContext *avctx)
{
LibSpeexContext *s = avctx->priv_data;
speex_bits_reset(&s->bits);
}
AVCodec ff_libspeex_decoder = {
.name = "libspeex",
.type = AVMEDIA_TYPE_AUDIO,
@ -146,5 +162,7 @@ AVCodec ff_libspeex_decoder = {
.init = libspeex_decode_init,
.close = libspeex_decode_close,
.decode = libspeex_decode_frame,
.flush = libspeex_decode_flush,
.capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY,
.long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
};