[FFmpeg-cvslog] dpcm: convert to bytestream2.
Ronald S. Bultje
git at videolan.org
Sun Mar 25 23:42:51 CEST 2012
ffmpeg | branch: master | Ronald S. Bultje <rsbultje at gmail.com> | Sun Mar 18 19:33:04 2012 -0700| [3a3f06b05eee7c3e9da781864a510eda1ff587b8] | committer: Ronald S. Bultje
dpcm: convert to bytestream2.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3a3f06b05eee7c3e9da781864a510eda1ff587b8
---
libavcodec/dpcm.c | 58 ++++++++++++++++++++++++++++------------------------
1 files changed, 31 insertions(+), 27 deletions(-)
diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c
index 7f5dbfe..2bd7978 100644
--- a/libavcodec/dpcm.c
+++ b/libavcodec/dpcm.c
@@ -40,6 +40,7 @@
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
+#include "mathops.h"
typedef struct DPCMContext {
AVFrame frame;
@@ -173,20 +174,18 @@ static av_cold int dpcm_decode_init(AVCodecContext *avctx)
static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
- const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
- const uint8_t *buf_end = buf + buf_size;
DPCMContext *s = avctx->priv_data;
int out = 0, ret;
int predictor[2];
int ch = 0;
int stereo = s->channels - 1;
- int16_t *output_samples;
+ int16_t *output_samples, *samples_end;
+ GetByteContext gb;
- if (stereo && (buf_size & 1)) {
+ if (stereo && (buf_size & 1))
buf_size--;
- buf_end--;
- }
+ bytestream2_init(&gb, avpkt->data, buf_size);
/* calculate output size */
switch(avctx->codec->id) {
@@ -218,22 +217,23 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
return ret;
}
output_samples = (int16_t *)s->frame.data[0];
+ samples_end = output_samples + out;
switch(avctx->codec->id) {
case CODEC_ID_ROQ_DPCM:
- buf += 6;
+ bytestream2_skipu(&gb, 6);
if (stereo) {
- predictor[1] = (int16_t)(bytestream_get_byte(&buf) << 8);
- predictor[0] = (int16_t)(bytestream_get_byte(&buf) << 8);
+ predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
+ predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
} else {
- predictor[0] = (int16_t)bytestream_get_le16(&buf);
+ predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
}
/* decode the samples */
- while (buf < buf_end) {
- predictor[ch] += s->roq_square_array[*buf++];
+ while (output_samples < samples_end) {
+ predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
predictor[ch] = av_clip_int16(predictor[ch]);
*output_samples++ = predictor[ch];
@@ -243,16 +243,16 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
break;
case CODEC_ID_INTERPLAY_DPCM:
- buf += 6; /* skip over the stream mask and stream length */
+ bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
for (ch = 0; ch < s->channels; ch++) {
- predictor[ch] = (int16_t)bytestream_get_le16(&buf);
+ predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
*output_samples++ = predictor[ch];
}
ch = 0;
- while (buf < buf_end) {
- predictor[ch] += interplay_delta_table[*buf++];
+ while (output_samples < samples_end) {
+ predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
predictor[ch] = av_clip_int16(predictor[ch]);
*output_samples++ = predictor[ch];
@@ -266,16 +266,19 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
int shift[2] = { 4, 4 };
for (ch = 0; ch < s->channels; ch++)
- predictor[ch] = (int16_t)bytestream_get_le16(&buf);
+ predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
ch = 0;
- while (buf < buf_end) {
- uint8_t n = *buf++;
- int16_t diff = (n & 0xFC) << 8;
- if ((n & 0x03) == 3)
+ while (output_samples < samples_end) {
+ int diff = bytestream2_get_byteu(&gb);
+ int n = diff & 3;
+
+ if (n == 3)
shift[ch]++;
else
- shift[ch] -= (2 * (n & 3));
+ shift[ch] -= (2 * n);
+ diff = sign_extend((diff &~ 3) << 8, 16);
+
/* saturate the shifter to a lower limit of 0 */
if (shift[ch] < 0)
shift[ch] = 0;
@@ -293,9 +296,10 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
}
case CODEC_ID_SOL_DPCM:
if (avctx->codec_tag != 3) {
- uint8_t *output_samples_u8 = s->frame.data[0];
- while (buf < buf_end) {
- uint8_t n = *buf++;
+ uint8_t *output_samples_u8 = s->frame.data[0],
+ *samples_end_u8 = output_samples_u8 + out;
+ while (output_samples_u8 < samples_end_u8) {
+ int n = bytestream2_get_byteu(&gb);
s->sample[0] += s->sol_table[n >> 4];
s->sample[0] = av_clip_uint8(s->sample[0]);
@@ -306,8 +310,8 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
*output_samples_u8++ = s->sample[stereo];
}
} else {
- while (buf < buf_end) {
- uint8_t n = *buf++;
+ while (output_samples < samples_end) {
+ int n = bytestream2_get_byteu(&gb);
if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
else s->sample[ch] += sol_table_16[n & 0x7F];
s->sample[ch] = av_clip_int16(s->sample[ch]);
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