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 "nellymoser.h"
35 #include "libavutil/lfg.h"
36 #include "libavutil/random_seed.h"
37 #include "libavutil/audioconvert.h"
41 #include "fmtconvert.h"
44 #define ALT_BITSTREAM_READER_LE
48 typedef struct NellyMoserDecodeContext {
49 AVCodecContext* avctx;
51 DECLARE_ALIGNED(16, float, state)[NELLY_BUF_LEN];
57 FmtConvertContext fmt_conv;
58 DECLARE_ALIGNED(32, float, imdct_out)[NELLY_BUF_LEN * 2];
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_calc(&s->imdct_ctx, s->imdct_out, aptr);
109 /* XXX: overlapping and windowing should be part of a more
110 generic imdct function */
111 s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
112 s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
113 memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
117 static av_cold int decode_init(AVCodecContext * avctx) {
118 NellyMoserDecodeContext *s = avctx->priv_data;
121 av_lfg_init(&s->random_state, 0);
122 ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
124 dsputil_init(&s->dsp, avctx);
126 if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
127 s->scale_bias = 1.0/(32768*8);
128 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
130 s->scale_bias = 1.0/(1*8);
131 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
132 ff_fmt_convert_init(&s->fmt_conv, avctx);
133 s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
135 av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
136 return AVERROR(ENOMEM);
140 /* Generate overlap window */
141 if (!ff_sine_128[127])
142 ff_init_ff_sine_windows(7);
144 avctx->channel_layout = AV_CH_LAYOUT_MONO;
148 static int decode_tag(AVCodecContext * avctx,
149 void *data, int *data_size,
151 const uint8_t *buf = avpkt->data;
152 int buf_size = avpkt->size;
153 NellyMoserDecodeContext *s = avctx->priv_data;
154 int blocks, i, block_size;
155 int16_t *samples_s16 = data;
156 float *samples_flt = data;
158 block_size = NELLY_SAMPLES * av_get_bytes_per_sample(avctx->sample_fmt);
159 blocks = buf_size / NELLY_BLOCK_LEN;
161 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
162 return AVERROR_INVALIDDATA;
164 if (*data_size < blocks * block_size) {
165 av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
166 return AVERROR(EINVAL);
168 if (buf_size % NELLY_BLOCK_LEN) {
169 av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
170 buf_size % NELLY_BLOCK_LEN);
172 /* Normal numbers of blocks for sample rates:
180 for (i=0 ; i<blocks ; i++) {
181 if (avctx->sample_fmt == SAMPLE_FMT_FLT) {
182 nelly_decode_block(s, buf, samples_flt);
183 samples_flt += NELLY_SAMPLES;
185 nelly_decode_block(s, buf, s->float_buf);
186 s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
187 samples_s16 += NELLY_SAMPLES;
189 buf += NELLY_BLOCK_LEN;
191 *data_size = blocks * block_size;
196 static av_cold int decode_end(AVCodecContext * avctx) {
197 NellyMoserDecodeContext *s = avctx->priv_data;
199 av_freep(&s->float_buf);
200 ff_mdct_end(&s->imdct_ctx);
204 AVCodec ff_nellymoser_decoder = {
205 .name = "nellymoser",
206 .type = AVMEDIA_TYPE_AUDIO,
207 .id = CODEC_ID_NELLYMOSER,
208 .priv_data_size = sizeof(NellyMoserDecodeContext),
211 .decode = decode_tag,
212 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
213 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
215 AV_SAMPLE_FMT_NONE },