2 * NellyMoser audio decoder
3 * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
4 * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
5 * 520e17cd55896441042b14df2566a6eb610ed444
6 * Copyright (c) 2007 Loic Minier <lool at dooz.org>
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 * DEALINGS IN THE SOFTWARE.
30 * The 3 alphanumeric copyright notices are md5summed they are from the original
31 * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/lfg.h"
36 #include "libavutil/random_seed.h"
40 #include "fmtconvert.h"
41 #include "nellymoser.h"
44 #define BITSTREAM_READER_LE
48 typedef struct NellyMoserDecodeContext {
49 AVCodecContext* avctx;
56 DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
59 } NellyMoserDecodeContext;
61 static void nelly_decode_block(NellyMoserDecodeContext *s,
62 const unsigned char block[NELLY_BLOCK_LEN],
63 float audio[NELLY_SAMPLES])
66 float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
67 float *aptr, *bptr, *pptr, val, pval;
68 int bits[NELLY_BUF_LEN];
71 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
75 val = ff_nelly_init_table[get_bits(&s->gb, 6)];
76 for (i=0 ; i<NELLY_BANDS ; i++) {
78 val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
79 pval = -pow(2, val/2048) * s->scale_bias;
80 for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
87 ff_nelly_get_sample_bits(buf, bits);
89 for (i = 0; i < 2; i++) {
90 aptr = audio + i * NELLY_BUF_LEN;
92 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
93 skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
95 for (j = 0; j < NELLY_FILL_LEN; j++) {
97 aptr[j] = M_SQRT1_2*pows[j];
98 if (av_lfg_get(&s->random_state) & 1)
101 v = get_bits(&s->gb, bits[j]);
102 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
105 memset(&aptr[NELLY_FILL_LEN], 0,
106 (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
108 s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
109 s->dsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN/2, s->imdct_out, ff_sine_128, NELLY_BUF_LEN/2);
110 FFSWAP(float *, s->imdct_out, s->imdct_prev);
114 static av_cold int decode_init(AVCodecContext * avctx) {
115 NellyMoserDecodeContext *s = avctx->priv_data;
118 s->imdct_out = s->imdct_buf[0];
119 s->imdct_prev = s->imdct_buf[1];
120 av_lfg_init(&s->random_state, 0);
121 ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
123 ff_dsputil_init(&s->dsp, avctx);
125 s->scale_bias = 1.0/(32768*8);
126 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
128 /* Generate overlap window */
129 if (!ff_sine_128[127])
130 ff_init_ff_sine_windows(7);
133 avctx->channel_layout = AV_CH_LAYOUT_MONO;
135 avcodec_get_frame_defaults(&s->frame);
136 avctx->coded_frame = &s->frame;
141 static int decode_tag(AVCodecContext *avctx, void *data,
142 int *got_frame_ptr, AVPacket *avpkt)
144 const uint8_t *buf = avpkt->data;
145 const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
146 int buf_size = avpkt->size;
147 NellyMoserDecodeContext *s = avctx->priv_data;
151 blocks = buf_size / NELLY_BLOCK_LEN;
154 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
155 return AVERROR_INVALIDDATA;
158 if (buf_size % NELLY_BLOCK_LEN) {
159 av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
160 buf_size % NELLY_BLOCK_LEN);
162 /* Normal numbers of blocks for sample rates:
169 if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
170 avctx->sample_rate= 11025*(blocks/2);
172 /* get output buffer */
173 s->frame.nb_samples = NELLY_SAMPLES * blocks;
174 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
175 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
178 samples_flt = (float *)s->frame.data[0];
180 for (i=0 ; i<blocks ; i++) {
181 nelly_decode_block(s, buf, samples_flt);
182 samples_flt += NELLY_SAMPLES;
183 buf += NELLY_BLOCK_LEN;
187 *(AVFrame *)data = s->frame;
192 static av_cold int decode_end(AVCodecContext * avctx) {
193 NellyMoserDecodeContext *s = avctx->priv_data;
195 ff_mdct_end(&s->imdct_ctx);
200 AVCodec ff_nellymoser_decoder = {
201 .name = "nellymoser",
202 .type = AVMEDIA_TYPE_AUDIO,
203 .id = AV_CODEC_ID_NELLYMOSER,
204 .priv_data_size = sizeof(NellyMoserDecodeContext),
207 .decode = decode_tag,
208 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
209 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
210 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
211 AV_SAMPLE_FMT_NONE },