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"
42 #include "nellymoser.h"
45 #define BITSTREAM_READER_LE
49 typedef struct NellyMoserDecodeContext {
50 AVCodecContext* avctx;
57 DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
60 } NellyMoserDecodeContext;
62 static void nelly_decode_block(NellyMoserDecodeContext *s,
63 const unsigned char block[NELLY_BLOCK_LEN],
64 float audio[NELLY_SAMPLES])
67 float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
68 float *aptr, *bptr, *pptr, val, pval;
69 int bits[NELLY_BUF_LEN];
72 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
76 val = ff_nelly_init_table[get_bits(&s->gb, 6)];
77 for (i=0 ; i<NELLY_BANDS ; i++) {
79 val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
80 pval = -pow(2, val/2048) * s->scale_bias;
81 for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
88 ff_nelly_get_sample_bits(buf, bits);
90 for (i = 0; i < 2; i++) {
91 aptr = audio + i * NELLY_BUF_LEN;
93 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
94 skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
96 for (j = 0; j < NELLY_FILL_LEN; j++) {
98 aptr[j] = M_SQRT1_2*pows[j];
99 if (av_lfg_get(&s->random_state) & 1)
102 v = get_bits(&s->gb, bits[j]);
103 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
106 memset(&aptr[NELLY_FILL_LEN], 0,
107 (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
109 s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
110 s->dsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN/2, s->imdct_out, ff_sine_128, NELLY_BUF_LEN/2);
111 FFSWAP(float *, s->imdct_out, s->imdct_prev);
115 static av_cold int decode_init(AVCodecContext * avctx) {
116 NellyMoserDecodeContext *s = avctx->priv_data;
119 s->imdct_out = s->imdct_buf[0];
120 s->imdct_prev = s->imdct_buf[1];
121 av_lfg_init(&s->random_state, 0);
122 ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
124 ff_dsputil_init(&s->dsp, avctx);
126 s->scale_bias = 1.0/(32768*8);
127 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
129 /* Generate overlap window */
130 if (!ff_sine_128[127])
131 ff_init_ff_sine_windows(7);
134 avctx->channel_layout = AV_CH_LAYOUT_MONO;
136 avcodec_get_frame_defaults(&s->frame);
137 avctx->coded_frame = &s->frame;
142 static int decode_tag(AVCodecContext *avctx, void *data,
143 int *got_frame_ptr, AVPacket *avpkt)
145 const uint8_t *buf = avpkt->data;
146 const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
147 int buf_size = avpkt->size;
148 NellyMoserDecodeContext *s = avctx->priv_data;
152 blocks = buf_size / NELLY_BLOCK_LEN;
155 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
156 return AVERROR_INVALIDDATA;
159 if (buf_size % NELLY_BLOCK_LEN) {
160 av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
161 buf_size % NELLY_BLOCK_LEN);
163 /* Normal numbers of blocks for sample rates:
170 if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
171 avctx->sample_rate= 11025*(blocks/2);
173 /* get output buffer */
174 s->frame.nb_samples = NELLY_SAMPLES * blocks;
175 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
176 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
179 samples_flt = (float *)s->frame.data[0];
181 for (i=0 ; i<blocks ; i++) {
182 nelly_decode_block(s, buf, samples_flt);
183 samples_flt += NELLY_SAMPLES;
184 buf += NELLY_BLOCK_LEN;
188 *(AVFrame *)data = s->frame;
193 static av_cold int decode_end(AVCodecContext * avctx) {
194 NellyMoserDecodeContext *s = avctx->priv_data;
196 ff_mdct_end(&s->imdct_ctx);
201 AVCodec ff_nellymoser_decoder = {
202 .name = "nellymoser",
203 .type = AVMEDIA_TYPE_AUDIO,
204 .id = AV_CODEC_ID_NELLYMOSER,
205 .priv_data_size = sizeof(NellyMoserDecodeContext),
208 .decode = decode_tag,
209 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
210 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
211 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
212 AV_SAMPLE_FMT_NONE },