RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-27 18:02:11 +00:00
Code Issues Projects Releases Wiki Activity

adpcm: convert adpcm_ea to bytestream2.

Browse Source
This commit is contained in:
Ronald S. Bultje 2012-03-17 14:43:20 -07:00
parent 524af484ed
commit 4a876eba8d
1 changed files with 24 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
libavcodec/adpcm.c
View File

@ -403,9 +403,7 @@ static int get_nb_samples(AVCodecContext *avctx, const uint8_t *buf,
switch (avctx->codec->id) {
case CODEC_ID_ADPCM_EA:
has_coded_samples = 1;
if (buf_size < 4)
return 0;
*coded_samples = AV_RL32(buf);
*coded_samples = bytestream2_get_le32(gb);
*coded_samples -= *coded_samples % 28;
nb_samples = (buf_size - 12) / 30 * 28;
break;
@ -868,37 +866,35 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
break;
case CODEC_ID_ADPCM_EA:
{
int32_t previous_left_sample, previous_right_sample;
int32_t current_left_sample, current_right_sample;
int32_t next_left_sample, next_right_sample;
int32_t coeff1l, coeff2l, coeff1r, coeff2r;
uint8_t shift_left, shift_right;
int previous_left_sample, previous_right_sample;
int current_left_sample, current_right_sample;
int next_left_sample, next_right_sample;
int coeff1l, coeff2l, coeff1r, coeff2r;
int shift_left, shift_right;
/* Each EA ADPCM frame has a 12-byte header followed by 30-byte pieces,
each coding 28 stereo samples. */
src += 4; // skip sample count (already read)
current_left_sample = (int16_t)bytestream_get_le16(&src);
previous_left_sample = (int16_t)bytestream_get_le16(&src);
current_right_sample = (int16_t)bytestream_get_le16(&src);
previous_right_sample = (int16_t)bytestream_get_le16(&src);
current_left_sample = sign_extend(bytestream2_get_le16u(&gb), 16);
previous_left_sample = sign_extend(bytestream2_get_le16u(&gb), 16);
current_right_sample = sign_extend(bytestream2_get_le16u(&gb), 16);
previous_right_sample = sign_extend(bytestream2_get_le16u(&gb), 16);
for (count1 = 0; count1 < nb_samples / 28; count1++) {
coeff1l = ea_adpcm_table[ *src >> 4 ];
coeff2l = ea_adpcm_table[(*src >> 4 ) + 4];
coeff1r = ea_adpcm_table[*src & 0x0F];
coeff2r = ea_adpcm_table[(*src & 0x0F) + 4];
src++;
int byte = bytestream2_get_byteu(&gb);
coeff1l = ea_adpcm_table[ byte >> 4 ];
coeff2l = ea_adpcm_table[(byte >> 4 ) + 4];
coeff1r = ea_adpcm_table[ byte & 0x0F];
coeff2r = ea_adpcm_table[(byte & 0x0F) + 4];
shift_left = 20 - (*src >> 4);
shift_right = 20 - (*src & 0x0F);
src++;
byte = bytestream2_get_byteu(&gb);
shift_left = 20 - (byte >> 4);
shift_right = 20 - (byte & 0x0F);
for (count2 = 0; count2 < 28; count2++) {
next_left_sample = sign_extend(*src >> 4, 4) << shift_left;
next_right_sample = sign_extend(*src, 4) << shift_right;
src++;
byte = bytestream2_get_byteu(&gb);
next_left_sample = sign_extend(byte >> 4, 4) << shift_left;
next_right_sample = sign_extend(byte, 4) << shift_right;
next_left_sample = (next_left_sample +
(current_left_sample * coeff1l) +
@ -911,13 +907,12 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
current_left_sample = av_clip_int16(next_left_sample);
previous_right_sample = current_right_sample;
current_right_sample = av_clip_int16(next_right_sample);
*samples++ = (unsigned short)current_left_sample;
*samples++ = (unsigned short)current_right_sample;
*samples++ = current_left_sample;
*samples++ = current_right_sample;
}
}
if (src - buf == buf_size - 2)
src += 2; // Skip terminating 0x0000
bytestream2_skip(&gb, 2); // Skip terminating 0x0000
break;
}