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 BITSTREAM_READER_LE
48 typedef struct NellyMoserDecodeContext {
49 AVCodecContext* avctx;
57 FmtConvertContext fmt_conv;
58 DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
61 } NellyMoserDecodeContext;
63 static void nelly_decode_block(NellyMoserDecodeContext *s,
64 const unsigned char block[NELLY_BLOCK_LEN],
65 float audio[NELLY_SAMPLES])
68 float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
69 float *aptr, *bptr, *pptr, val, pval;
70 int bits[NELLY_BUF_LEN];
73 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
77 val = ff_nelly_init_table[get_bits(&s->gb, 6)];
78 for (i=0 ; i<NELLY_BANDS ; i++) {
80 val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
81 pval = -pow(2, val/2048) * s->scale_bias;
82 for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
89 ff_nelly_get_sample_bits(buf, bits);
91 for (i = 0; i < 2; i++) {
92 aptr = audio + i * NELLY_BUF_LEN;
94 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
95 skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
97 for (j = 0; j < NELLY_FILL_LEN; j++) {
99 aptr[j] = M_SQRT1_2*pows[j];
100 if (av_lfg_get(&s->random_state) & 1)
103 v = get_bits(&s->gb, bits[j]);
104 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
107 memset(&aptr[NELLY_FILL_LEN], 0,
108 (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
110 s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
111 s->dsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN/2, s->imdct_out, ff_sine_128, NELLY_BUF_LEN/2);
112 FFSWAP(float *, s->imdct_out, s->imdct_prev);
116 static av_cold int decode_init(AVCodecContext * avctx) {
117 NellyMoserDecodeContext *s = avctx->priv_data;
120 s->imdct_out = s->imdct_buf[0];
121 s->imdct_prev = s->imdct_buf[1];
122 av_lfg_init(&s->random_state, 0);
123 ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
125 ff_dsputil_init(&s->dsp, avctx);
127 if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
128 s->scale_bias = 1.0/(32768*8);
129 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
131 s->scale_bias = 1.0/(1*8);
132 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
133 ff_fmt_convert_init(&s->fmt_conv, avctx);
134 s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
136 av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
137 return AVERROR(ENOMEM);
141 /* Generate overlap window */
142 if (!ff_sine_128[127])
143 ff_init_ff_sine_windows(7);
145 avctx->channel_layout = AV_CH_LAYOUT_MONO;
147 avcodec_get_frame_defaults(&s->frame);
148 avctx->coded_frame = &s->frame;
153 static int decode_tag(AVCodecContext *avctx, void *data,
154 int *got_frame_ptr, AVPacket *avpkt)
156 const uint8_t *buf = avpkt->data;
157 const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
158 int buf_size = avpkt->size;
159 NellyMoserDecodeContext *s = avctx->priv_data;
161 int16_t *samples_s16;
164 blocks = buf_size / NELLY_BLOCK_LEN;
167 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
168 return AVERROR_INVALIDDATA;
171 if (buf_size % NELLY_BLOCK_LEN) {
172 av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
173 buf_size % NELLY_BLOCK_LEN);
175 /* Normal numbers of blocks for sample rates:
182 if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
183 avctx->sample_rate= 11025*(blocks/2);
185 /* get output buffer */
186 s->frame.nb_samples = NELLY_SAMPLES * blocks;
187 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
188 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
191 samples_s16 = (int16_t *)s->frame.data[0];
192 samples_flt = (float *)s->frame.data[0];
194 for (i=0 ; i<blocks ; i++) {
195 if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
196 nelly_decode_block(s, buf, samples_flt);
197 samples_flt += NELLY_SAMPLES;
199 nelly_decode_block(s, buf, s->float_buf);
200 s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
201 samples_s16 += NELLY_SAMPLES;
203 buf += NELLY_BLOCK_LEN;
207 *(AVFrame *)data = s->frame;
212 static av_cold int decode_end(AVCodecContext * avctx) {
213 NellyMoserDecodeContext *s = avctx->priv_data;
215 av_freep(&s->float_buf);
216 ff_mdct_end(&s->imdct_ctx);
221 AVCodec ff_nellymoser_decoder = {
222 .name = "nellymoser",
223 .type = AVMEDIA_TYPE_AUDIO,
224 .id = AV_CODEC_ID_NELLYMOSER,
225 .priv_data_size = sizeof(NellyMoserDecodeContext),
228 .decode = decode_tag,
229 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
230 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
231 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
233 AV_SAMPLE_FMT_NONE },