From 704721bc9cb47c58ce3dff8ef64ce3fb85283069 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Sat, 22 Oct 2011 17:49:50 -0400 Subject: g722: split decoder and encoder into separate files --- libavcodec/g722dec.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 libavcodec/g722dec.c (limited to 'libavcodec/g722dec.c') diff --git a/libavcodec/g722dec.c b/libavcodec/g722dec.c new file mode 100644 index 0000000000..51f87c9d3c --- /dev/null +++ b/libavcodec/g722dec.c @@ -0,0 +1,147 @@ +/* + * Copyright (c) CMU 1993 Computer Science, Speech Group + * Chengxiang Lu and Alex Hauptmann + * Copyright (c) 2005 Steve Underwood + * Copyright (c) 2009 Kenan Gillet + * Copyright (c) 2010 Martin Storsjo + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * G.722 ADPCM audio decoder + * + * This G.722 decoder is a bit-exact implementation of the ITU G.722 + * specification for all three specified bitrates - 64000bps, 56000bps + * and 48000bps. It passes the ITU tests. + * + * @note For the 56000bps and 48000bps bitrates, the lowest 1 or 2 bits + * respectively of each byte are ignored. + */ + +#include "avcodec.h" +#include "get_bits.h" +#include "g722.h" + +static av_cold int g722_decode_init(AVCodecContext * avctx) +{ + G722Context *c = avctx->priv_data; + + if (avctx->channels != 1) { + av_log(avctx, AV_LOG_ERROR, "Only mono tracks are allowed.\n"); + return AVERROR_INVALIDDATA; + } + avctx->sample_fmt = AV_SAMPLE_FMT_S16; + + switch (avctx->bits_per_coded_sample) { + case 8: + case 7: + case 6: + break; + default: + av_log(avctx, AV_LOG_WARNING, "Unsupported bits_per_coded_sample [%d], " + "assuming 8\n", + avctx->bits_per_coded_sample); + case 0: + avctx->bits_per_coded_sample = 8; + break; + } + + c->band[0].scale_factor = 8; + c->band[1].scale_factor = 2; + c->prev_samples_pos = 22; + + if (avctx->lowres) + avctx->sample_rate /= 2; + + return 0; +} + +static const int16_t low_inv_quant5[32] = { + -35, -35, -2919, -2195, -1765, -1458, -1219, -1023, + -858, -714, -587, -473, -370, -276, -190, -110, + 2919, 2195, 1765, 1458, 1219, 1023, 858, 714, + 587, 473, 370, 276, 190, 110, 35, -35 +}; + +static const int16_t *low_inv_quants[3] = { ff_g722_low_inv_quant6, + low_inv_quant5, + ff_g722_low_inv_quant4 }; + +static int g722_decode_frame(AVCodecContext *avctx, void *data, + int *data_size, AVPacket *avpkt) +{ + G722Context *c = avctx->priv_data; + int16_t *out_buf = data; + int j, out_len = 0; + const int skip = 8 - avctx->bits_per_coded_sample; + const int16_t *quantizer_table = low_inv_quants[skip]; + GetBitContext gb; + + init_get_bits(&gb, avpkt->data, avpkt->size * 8); + + for (j = 0; j < avpkt->size; j++) { + int ilow, ihigh, rlow; + + ihigh = get_bits(&gb, 2); + ilow = get_bits(&gb, 6 - skip); + skip_bits(&gb, skip); + + rlow = av_clip((c->band[0].scale_factor * quantizer_table[ilow] >> 10) + + c->band[0].s_predictor, -16384, 16383); + + ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip)); + + if (!avctx->lowres) { + const int dhigh = c->band[1].scale_factor * + ff_g722_high_inv_quant[ihigh] >> 10; + const int rhigh = av_clip(dhigh + c->band[1].s_predictor, + -16384, 16383); + int xout1, xout2; + + ff_g722_update_high_predictor(&c->band[1], dhigh, ihigh); + + c->prev_samples[c->prev_samples_pos++] = rlow + rhigh; + c->prev_samples[c->prev_samples_pos++] = rlow - rhigh; + ff_g722_apply_qmf(c->prev_samples + c->prev_samples_pos - 24, + &xout1, &xout2); + out_buf[out_len++] = av_clip_int16(xout1 >> 12); + out_buf[out_len++] = av_clip_int16(xout2 >> 12); + if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) { + memmove(c->prev_samples, + c->prev_samples + c->prev_samples_pos - 22, + 22 * sizeof(c->prev_samples[0])); + c->prev_samples_pos = 22; + } + } else + out_buf[out_len++] = rlow; + } + *data_size = out_len << 1; + return avpkt->size; +} + +AVCodec ff_adpcm_g722_decoder = { + .name = "g722", + .type = AVMEDIA_TYPE_AUDIO, + .id = CODEC_ID_ADPCM_G722, + .priv_data_size = sizeof(G722Context), + .init = g722_decode_init, + .decode = g722_decode_frame, + .long_name = NULL_IF_CONFIG_SMALL("G.722 ADPCM"), + .max_lowres = 1, +}; -- cgit v1.2.3