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1 /*
2  * codec2 encoder/decoder using libcodec2
3  * Copyright (c) 2017 Tomas Härdin
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <codec2/codec2.h>
23 #include "libavutil/channel_layout.h"
24 #include "avcodec.h"
25 #include "libavutil/opt.h"
26 #include "codec_internal.h"
27 #include "encode.h"
28 #include "internal.h"
29 #include "codec2utils.h"
30 
31 typedef struct {
32     const AVClass *class;
33     struct CODEC2 *codec;
34     int mode;
35 } LibCodec2Context;
36 
37 static const AVOption options[] = {
38     //not AV_OPT_FLAG_DECODING_PARAM since mode should come from the demuxer
39     //1300 (aka FreeDV 1600) is the most common mode on-the-air, default to it here as well
40     CODEC2_AVOPTIONS("codec2 mode", LibCodec2Context, 0, 4 /*CODEC2_MODE_1300*/, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_ENCODING_PARAM),
41     { NULL },
42 };
43 
44 static const AVClass libcodec2_enc_class = {
45     .class_name = "libcodec2 encoder",
46     .item_name  = av_default_item_name,
47     .option     = options,
48     .version    = LIBAVUTIL_VERSION_INT,
49 };
50 
libcodec2_init_common(AVCodecContext * avctx,int mode)51 static av_cold int libcodec2_init_common(AVCodecContext *avctx, int mode)
52 {
53     LibCodec2Context *c2 = avctx->priv_data;
54     //Grab mode name from options, unless it's some weird number.
55     const char *modename = mode >= 0 && mode <= CODEC2_MODE_MAX ? options[mode+1].name : "?";
56 
57     c2->codec = codec2_create(mode);
58     if (!c2->codec) {
59         //Out of memory or unsupported mode. The latter seems most likely,
60         //but we can't tell for sure with the current API.
61         goto libcodec2_init_common_error;
62     }
63 
64     avctx->frame_size = codec2_samples_per_frame(c2->codec);
65     avctx->block_align = (codec2_bits_per_frame(c2->codec) + 7) / 8;
66 
67     if (avctx->frame_size <= 0 || avctx->block_align <= 0) {
68         //codec2_create() may succeed for some modes but still fail at codec2_samples_per_frame()
69         //example is -mode 700C on libcodec2 0.4
70         codec2_destroy(c2->codec);
71         c2->codec = NULL;
72         goto libcodec2_init_common_error;
73     }
74 
75     codec2_set_natural_or_gray(c2->codec, 1);
76 
77     return 0;
78 
79 libcodec2_init_common_error:
80     av_log(avctx, AV_LOG_ERROR,
81         "Mode %i (%s) not supported with the linked version of libcodec2\n",
82         mode, modename);
83     return AVERROR(EINVAL);
84 }
85 
libcodec2_init_decoder(AVCodecContext * avctx)86 static av_cold int libcodec2_init_decoder(AVCodecContext *avctx)
87 {
88     avctx->sample_rate      = 8000;
89     avctx->sample_fmt       = AV_SAMPLE_FMT_S16;
90     av_channel_layout_uninit(&avctx->ch_layout);
91     avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
92 
93     if (avctx->extradata_size != CODEC2_EXTRADATA_SIZE) {
94         av_log(avctx, AV_LOG_ERROR, "must have exactly %i bytes of extradata (got %i)\n",
95                CODEC2_EXTRADATA_SIZE, avctx->extradata_size);
96         return AVERROR_INVALIDDATA;
97     }
98 
99     return libcodec2_init_common(avctx, codec2_mode_from_extradata(avctx->extradata));
100 }
101 
libcodec2_init_encoder(AVCodecContext * avctx)102 static av_cold int libcodec2_init_encoder(AVCodecContext *avctx)
103 {
104     LibCodec2Context *c2 = avctx->priv_data;
105 
106     //will need to be smarter once we get wideband support
107     if (avctx->sample_rate != 8000 ||
108         avctx->ch_layout.nb_channels != 1 ||
109         avctx->sample_fmt != AV_SAMPLE_FMT_S16) {
110         av_log(avctx, AV_LOG_ERROR, "only 8 kHz 16-bit mono allowed\n");
111         return AVERROR(EINVAL);
112     }
113 
114     avctx->extradata = av_mallocz(CODEC2_EXTRADATA_SIZE + AV_INPUT_BUFFER_PADDING_SIZE);
115     if (!avctx->extradata) {
116         return AVERROR(ENOMEM);
117     }
118 
119     avctx->extradata_size = CODEC2_EXTRADATA_SIZE;
120     codec2_make_extradata(avctx->extradata, c2->mode);
121 
122     return libcodec2_init_common(avctx, c2->mode);
123 }
124 
libcodec2_close(AVCodecContext * avctx)125 static av_cold int libcodec2_close(AVCodecContext *avctx)
126 {
127     LibCodec2Context *c2 = avctx->priv_data;
128 
129     codec2_destroy(c2->codec);
130     return 0;
131 }
132 
libcodec2_decode(AVCodecContext * avctx,AVFrame * frame,int * got_frame_ptr,AVPacket * pkt)133 static int libcodec2_decode(AVCodecContext *avctx, AVFrame *frame,
134                             int *got_frame_ptr, AVPacket *pkt)
135 {
136     LibCodec2Context *c2 = avctx->priv_data;
137     int ret, nframes, i;
138     const uint8_t *input;
139     int16_t *output;
140 
141     nframes           = pkt->size / avctx->block_align;
142     frame->nb_samples = avctx->frame_size * nframes;
143 
144     ret = ff_get_buffer(avctx, frame, 0);
145     if (ret < 0) {
146         return ret;
147     }
148 
149     input  = pkt->data;
150     output = (int16_t *)frame->data[0];
151 
152     for (i = 0; i < nframes; i++) {
153         codec2_decode(c2->codec, output, input);
154         input  += avctx->block_align;
155         output += avctx->frame_size;
156     }
157 
158     *got_frame_ptr = nframes > 0;
159     return nframes * avctx->block_align;
160 }
161 
libcodec2_encode(AVCodecContext * avctx,AVPacket * avpkt,const AVFrame * frame,int * got_packet_ptr)162 static int libcodec2_encode(AVCodecContext *avctx, AVPacket *avpkt,
163                             const AVFrame *frame, int *got_packet_ptr)
164 {
165     LibCodec2Context *c2 = avctx->priv_data;
166     int16_t *samples = (int16_t *)frame->data[0];
167 
168     int ret = ff_get_encode_buffer(avctx, avpkt, avctx->block_align, 0);
169     if (ret < 0) {
170         return ret;
171     }
172 
173     codec2_encode(c2->codec, avpkt->data, samples);
174     *got_packet_ptr = 1;
175 
176     return 0;
177 }
178 
179 const FFCodec ff_libcodec2_decoder = {
180     .p.name                 = "libcodec2",
181     .p.long_name            = NULL_IF_CONFIG_SMALL("codec2 decoder using libcodec2"),
182     .p.type                 = AVMEDIA_TYPE_AUDIO,
183     .p.id                   = AV_CODEC_ID_CODEC2,
184     .p.capabilities         = AV_CODEC_CAP_CHANNEL_CONF,
185     .p.supported_samplerates = (const int[]){ 8000, 0 },
186     .p.sample_fmts          = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
187     .p.ch_layouts           = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO, { 0 } },
188     .priv_data_size         = sizeof(LibCodec2Context),
189     .init                   = libcodec2_init_decoder,
190     .close                  = libcodec2_close,
191     FF_CODEC_DECODE_CB(libcodec2_decode),
192 #if FF_API_OLD_CHANNEL_LAYOUT
193     .p.channel_layouts      = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
194 #endif
195 };
196 
197 const FFCodec ff_libcodec2_encoder = {
198     .p.name                 = "libcodec2",
199     .p.long_name            = NULL_IF_CONFIG_SMALL("codec2 encoder using libcodec2"),
200     .p.type                 = AVMEDIA_TYPE_AUDIO,
201     .p.id                   = AV_CODEC_ID_CODEC2,
202     .p.capabilities         = AV_CODEC_CAP_DR1,
203     .p.supported_samplerates = (const int[]){ 8000, 0 },
204     .p.sample_fmts          = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
205     .p.ch_layouts           = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO, { 0 } },
206     .p.priv_class           = &libcodec2_enc_class,
207     .priv_data_size         = sizeof(LibCodec2Context),
208     .init                   = libcodec2_init_encoder,
209     .close                  = libcodec2_close,
210     FF_CODEC_ENCODE_CB(libcodec2_encode),
211 #if FF_API_OLD_CHANNEL_LAYOUT
212     .p.channel_layouts      = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
213 #endif
214 };
215