| /* | |
| * ADX ADPCM codecs | |
| * Copyright (c) 2001,2003 BERO | |
| * | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg 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. | |
| * | |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| #include "libavutil/intreadwrite.h" | |
| #include "avcodec.h" | |
| #include "adx.h" | |
| #include "codec_internal.h" | |
| #include "decode.h" | |
| #include "get_bits.h" | |
| /** | |
| * @file | |
| * SEGA CRI adx codecs. | |
| * | |
| * Reference documents: | |
| * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html | |
| * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ | |
| */ | |
| /** | |
| * Decode ADX stream header. | |
| * Sets avctx->channels and avctx->sample_rate. | |
| * | |
| * @param avctx codec context | |
| * @param buf header data | |
| * @param bufsize data size, should be at least 24 bytes | |
| * @param[out] header_size size of ADX header | |
| * @param[out] coeff 2 LPC coefficients, can be NULL | |
| * @return data offset or negative error code if header is invalid | |
| */ | |
| static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, | |
| int bufsize, int *header_size, int *coeff) | |
| { | |
| int offset, cutoff, channels; | |
| if (bufsize < 24) | |
| return AVERROR_INVALIDDATA; | |
| if (AV_RB16(buf) != 0x8000) | |
| return AVERROR_INVALIDDATA; | |
| offset = AV_RB16(buf + 2) + 4; | |
| /* if copyright string is within the provided data, validate it */ | |
| if (bufsize >= offset && offset >= 6 && memcmp(buf + offset - 6, "(c)CRI", 6)) | |
| return AVERROR_INVALIDDATA; | |
| /* check for encoding=3 block_size=18, sample_size=4 */ | |
| if (buf[4] != 3 || buf[5] != 18 || buf[6] != 4) { | |
| avpriv_request_sample(avctx, "Support for this ADX format"); | |
| return AVERROR_PATCHWELCOME; | |
| } | |
| /* channels */ | |
| channels = buf[7]; | |
| if (channels <= 0 || channels > MAX_CHANNELS) | |
| return AVERROR_INVALIDDATA; | |
| if (avctx->ch_layout.nb_channels != channels) { | |
| av_channel_layout_uninit(&avctx->ch_layout); | |
| avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC; | |
| avctx->ch_layout.nb_channels = channels; | |
| } | |
| /* sample rate */ | |
| avctx->sample_rate = AV_RB32(buf + 8); | |
| if (avctx->sample_rate < 1 || | |
| avctx->sample_rate > INT_MAX / (channels * BLOCK_SIZE * 8)) | |
| return AVERROR_INVALIDDATA; | |
| /* bit rate */ | |
| avctx->bit_rate = avctx->sample_rate * channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES; | |
| /* LPC coefficients */ | |
| if (coeff) { | |
| cutoff = AV_RB16(buf + 16); | |
| ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, coeff); | |
| } | |
| *header_size = offset; | |
| return 0; | |
| } | |
| static av_cold int adx_decode_init(AVCodecContext *avctx) | |
| { | |
| ADXContext *c = avctx->priv_data; | |
| int ret, header_size; | |
| if (avctx->extradata_size >= 24) { | |
| if ((ret = adx_decode_header(avctx, avctx->extradata, | |
| avctx->extradata_size, &header_size, | |
| c->coeff)) < 0) { | |
| av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n"); | |
| return AVERROR_INVALIDDATA; | |
| } | |
| c->channels = avctx->ch_layout.nb_channels; | |
| c->header_parsed = 1; | |
| } | |
| avctx->sample_fmt = AV_SAMPLE_FMT_S16P; | |
| return 0; | |
| } | |
| /** | |
| * Decode 32 samples from 18 bytes. | |
| * | |
| * A 16-bit scalar value is applied to 32 residuals, which then have a | |
| * 2nd-order LPC filter applied to it to form the output signal for a single | |
| * channel. | |
| */ | |
| static int adx_decode(ADXContext *c, int16_t *out, int offset, | |
| const uint8_t *in, int ch) | |
| { | |
| ADXChannelState *prev = &c->prev[ch]; | |
| GetBitContext gb; | |
| int scale = AV_RB16(in); | |
| int i; | |
| int s0, s1, s2, d; | |
| /* check if this is an EOF packet */ | |
| if (scale & 0x8000) | |
| return -1; | |
| init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8); | |
| out += offset; | |
| s1 = prev->s1; | |
| s2 = prev->s2; | |
| for (i = 0; i < BLOCK_SAMPLES; i++) { | |
| d = get_sbits(&gb, 4); | |
| s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS); | |
| s2 = s1; | |
| s1 = av_clip_int16(s0); | |
| *out++ = s1; | |
| } | |
| prev->s1 = s1; | |
| prev->s2 = s2; | |
| return 0; | |
| } | |
| static int adx_decode_frame(AVCodecContext *avctx, AVFrame *frame, | |
| int *got_frame_ptr, AVPacket *avpkt) | |
| { | |
| int buf_size = avpkt->size; | |
| ADXContext *c = avctx->priv_data; | |
| int16_t **samples; | |
| int samples_offset; | |
| const uint8_t *buf = avpkt->data; | |
| const uint8_t *buf_end = buf + avpkt->size; | |
| int num_blocks, ch, ret; | |
| size_t new_extradata_size; | |
| uint8_t *new_extradata; | |
| new_extradata = av_packet_get_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA, | |
| &new_extradata_size); | |
| if (new_extradata && new_extradata_size > 0) { | |
| int header_size; | |
| if ((ret = adx_decode_header(avctx, new_extradata, | |
| new_extradata_size, &header_size, | |
| c->coeff)) < 0) { | |
| av_log(avctx, AV_LOG_ERROR, "error parsing new ADX extradata\n"); | |
| return AVERROR_INVALIDDATA; | |
| } | |
| c->eof = 0; | |
| } | |
| if (c->eof) { | |
| *got_frame_ptr = 0; | |
| return buf_size; | |
| } | |
| if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) { | |
| int header_size; | |
| if ((ret = adx_decode_header(avctx, buf, buf_size, &header_size, | |
| c->coeff)) < 0) { | |
| av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n"); | |
| return AVERROR_INVALIDDATA; | |
| } | |
| c->channels = avctx->ch_layout.nb_channels; | |
| c->header_parsed = 1; | |
| if (buf_size < header_size) | |
| return AVERROR_INVALIDDATA; | |
| buf += header_size; | |
| buf_size -= header_size; | |
| } | |
| if (!c->header_parsed) | |
| return AVERROR_INVALIDDATA; | |
| /* calculate number of blocks in the packet */ | |
| num_blocks = buf_size / (BLOCK_SIZE * c->channels); | |
| /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF | |
| packet */ | |
| if (!num_blocks || buf_size % (BLOCK_SIZE * c->channels)) { | |
| if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) { | |
| c->eof = 1; | |
| *got_frame_ptr = 0; | |
| return avpkt->size; | |
| } | |
| return AVERROR_INVALIDDATA; | |
| } | |
| /* get output buffer */ | |
| frame->nb_samples = num_blocks * BLOCK_SAMPLES; | |
| if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) | |
| return ret; | |
| samples = (int16_t **)frame->extended_data; | |
| samples_offset = 0; | |
| while (num_blocks--) { | |
| for (ch = 0; ch < c->channels; ch++) { | |
| if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) { | |
| c->eof = 1; | |
| buf = avpkt->data + avpkt->size; | |
| break; | |
| } | |
| buf_size -= BLOCK_SIZE; | |
| buf += BLOCK_SIZE; | |
| } | |
| if (!c->eof) | |
| samples_offset += BLOCK_SAMPLES; | |
| } | |
| frame->nb_samples = samples_offset; | |
| *got_frame_ptr = 1; | |
| return buf - avpkt->data; | |
| } | |
| static void adx_decode_flush(AVCodecContext *avctx) | |
| { | |
| ADXContext *c = avctx->priv_data; | |
| memset(c->prev, 0, sizeof(c->prev)); | |
| c->eof = 0; | |
| } | |
| const FFCodec ff_adpcm_adx_decoder = { | |
| .p.name = "adpcm_adx", | |
| CODEC_LONG_NAME("SEGA CRI ADX ADPCM"), | |
| .p.type = AVMEDIA_TYPE_AUDIO, | |
| .p.id = AV_CODEC_ID_ADPCM_ADX, | |
| .priv_data_size = sizeof(ADXContext), | |
| .init = adx_decode_init, | |
| FF_CODEC_DECODE_CB(adx_decode_frame), | |
| .flush = adx_decode_flush, | |
| .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF | | |
| AV_CODEC_CAP_DR1, | |
| .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, | |
| AV_SAMPLE_FMT_NONE }, | |
| }; |