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authorRonald S. Bultje <rsbultje@gmail.com>2012-03-17 12:45:09 -0700
committerRonald S. Bultje <rsbultje@gmail.com>2012-03-18 15:25:25 -0700
commit9604307dd89745071611e6e2898a78460bb61fcb (patch)
tree8d562287e490f189b437aa008565248c852d3561 /libavcodec/adpcm.c
parentc346f6304c35e9dfffacc6c71a2b3dfd8913d90b (diff)
downloadffmpeg-9604307dd89745071611e6e2898a78460bb61fcb.tar.gz
adpcm: convert adpcm_ima_qt to bytestream2.
Diffstat (limited to 'libavcodec/adpcm.c')
-rw-r--r--libavcodec/adpcm.c27
1 files changed, 14 insertions, 13 deletions
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 3610a58812..1f61c56d80 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -544,6 +544,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
int st; /* stereo */
int count1, count2;
int nb_samples, coded_samples, ret;
+ GetByteContext gb;
nb_samples = get_nb_samples(avctx, buf, buf_size, &coded_samples);
if (nb_samples <= 0) {
@@ -568,6 +569,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
}
src = buf;
+ bytestream2_init(&gb, buf, buf_size);
st = avctx->channels == 2 ? 1 : 0;
@@ -576,20 +578,18 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
/* In QuickTime, IMA is encoded by chunks of 34 bytes (=64 samples).
Channel data is interleaved per-chunk. */
for (channel = 0; channel < avctx->channels; channel++) {
- int16_t predictor;
+ int predictor;
int step_index;
cs = &(c->status[channel]);
/* (pppppp) (piiiiiii) */
/* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
- predictor = AV_RB16(src);
+ predictor = sign_extend(bytestream2_get_be16u(&gb), 16);
step_index = predictor & 0x7F;
- predictor &= 0xFF80;
-
- src += 2;
+ predictor &= ~0x7F;
if (cs->step_index == step_index) {
- int diff = (int)predictor - cs->predictor;
+ int diff = predictor - cs->predictor;
if (diff < 0)
diff = - diff;
if (diff > 0x7f)
@@ -600,19 +600,20 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
cs->predictor = predictor;
}
- if (cs->step_index > 88){
- av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n", cs->step_index);
- cs->step_index = 88;
+ if (cs->step_index > 88u){
+ av_log(avctx, AV_LOG_ERROR, "ERROR: step_index[%d] = %i\n",
+ channel, cs->step_index);
+ return AVERROR_INVALIDDATA;
}
samples = (short *)c->frame.data[0] + channel;
for (m = 0; m < 32; m++) {
- *samples = adpcm_ima_qt_expand_nibble(cs, src[0] & 0x0F, 3);
+ int byte = bytestream2_get_byteu(&gb);
+ *samples = adpcm_ima_qt_expand_nibble(cs, byte & 0x0F, 3);
samples += avctx->channels;
- *samples = adpcm_ima_qt_expand_nibble(cs, src[0] >> 4 , 3);
+ *samples = adpcm_ima_qt_expand_nibble(cs, byte >> 4 , 3);
samples += avctx->channels;
- src ++;
}
}
break;
@@ -1239,7 +1240,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
*got_frame_ptr = 1;
*(AVFrame *)data = c->frame;
- return src - buf;
+ return src == buf ? bytestream2_tell(&gb) : src - buf;
}