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| author | aaron <aaronrules5alt@gmail.com> | 2024-07-21 11:18:02 +1000 |
|---|---|---|
| committer | Peter Ross <pross@xvid.org> | 2024-07-23 06:40:30 +1000 |
| commit | f44353cfb65ef9d54febbc552cacea52675bb8d1 (patch) | |
| tree | fa6fd8a3de7fa772cf2e7df24dc0f7a24ca5e798 /libavcodec/adpcm.c | |
| parent | 0e32192548cd38a206ef3ed3c0ad8edc337a1e5f (diff) | |
| download | ffmpeg-f44353cfb65ef9d54febbc552cacea52675bb8d1.tar.gz | |
avcodec/adpcm: Mono ADPCM for EA WVE Files
Reviewed-by: Peter Ross <pross@xvid.org>
Diffstat (limited to 'libavcodec/adpcm.c')
| -rw-r--r-- | libavcodec/adpcm.c | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c index f63afefd63..afdbeaa15e 100644 --- a/libavcodec/adpcm.c +++ b/libavcodec/adpcm.c @@ -262,7 +262,7 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx) break; case AV_CODEC_ID_ADPCM_DTK: case AV_CODEC_ID_ADPCM_EA: - min_channels = 2; + min_channels = 1; break; case AV_CODEC_ID_ADPCM_AFC: case AV_CODEC_ID_ADPCM_EA_R1: @@ -914,10 +914,12 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb, bytestream2_seek(gb, -8, SEEK_CUR); break; case AV_CODEC_ID_ADPCM_EA: + /* Stereo is 30 bytes per block */ + /* Mono is 15 bytes per block */ has_coded_samples = 1; *coded_samples = bytestream2_get_le32(gb); *coded_samples -= *coded_samples % 28; - nb_samples = (buf_size - 12) / 30 * 28; + nb_samples = (buf_size - 12) / (ch == 2 ? 30 : 15) * 28; break; case AV_CODEC_ID_ADPCM_IMA_EA_EACS: has_coded_samples = 1; @@ -1652,10 +1654,10 @@ static int adpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame, 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. */ + /* Each EA ADPCM frame has a 12-byte header followed by 30-byte (stereo) or 15-byte (mono) pieces, + each coding 28 stereo/mono samples. */ - if (channels != 2) + if (channels != 2 && channels != 1) return AVERROR_INVALIDDATA; current_left_sample = sign_extend(bytestream2_get_le16u(&gb), 16); @@ -1670,11 +1672,16 @@ static int adpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame, coeff1r = ea_adpcm_table[ byte & 0x0F]; coeff2r = ea_adpcm_table[(byte & 0x0F) + 4]; - byte = bytestream2_get_byteu(&gb); - shift_left = 20 - (byte >> 4); - shift_right = 20 - (byte & 0x0F); + if (channels == 2){ + byte = bytestream2_get_byteu(&gb); + shift_left = 20 - (byte >> 4); + shift_right = 20 - (byte & 0x0F); + } else{ + /* Mono packs the shift into the coefficient byte's lower nibble instead */ + shift_left = 20 - (byte & 0x0F); + } - for (int count2 = 0; count2 < 28; count2++) { + for (int count2 = 0; count2 < (channels == 2 ? 28 : 14); count2++) { byte = bytestream2_get_byteu(&gb); next_left_sample = sign_extend(byte >> 4, 4) * (1 << shift_left); next_right_sample = sign_extend(byte, 4) * (1 << shift_right); @@ -1691,11 +1698,24 @@ static int adpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame, previous_right_sample = current_right_sample; current_right_sample = av_clip_int16(next_right_sample); *samples++ = current_left_sample; - *samples++ = current_right_sample; + + if (channels == 2){ + *samples++ = current_right_sample; + } else { + next_left_sample = sign_extend(byte, 4) * (1 << shift_left); + + next_left_sample = (next_left_sample + + (current_left_sample * coeff1l) + + (previous_left_sample * coeff2l) + 0x80) >> 8; + + previous_left_sample = current_left_sample; + current_left_sample = av_clip_int16(next_left_sample); + + *samples++ = current_left_sample; + } } } - - bytestream2_skip(&gb, 2); // Skip terminating 0x0000 + bytestream2_skip(&gb, channels == 2 ? 2 : 3); // Skip terminating NULs ) /* End of CASE */ CASE(ADPCM_EA_MAXIS_XA, int coeff[2][2], shift[2]; |