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1 /*
2  * Interface to libshine for mp3 encoding
3  * Copyright (c) 2012 Paul B Mahol
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 <shine/layer3.h>
23 
24 #include "libavutil/intreadwrite.h"
25 #include "audio_frame_queue.h"
26 #include "avcodec.h"
27 #include "internal.h"
28 #include "mpegaudio.h"
29 #include "mpegaudiodecheader.h"
30 
31 #define BUFFER_SIZE (4096 * 20)
32 
33 typedef struct SHINEContext {
34     shine_config_t  config;
35     shine_t         shine;
36     uint8_t         buffer[BUFFER_SIZE];
37     int             buffer_index;
38     AudioFrameQueue afq;
39 } SHINEContext;
40 
libshine_encode_init(AVCodecContext * avctx)41 static av_cold int libshine_encode_init(AVCodecContext *avctx)
42 {
43     SHINEContext *s = avctx->priv_data;
44 
45     if (avctx->channels <= 0 || avctx->channels > 2){
46         av_log(avctx, AV_LOG_ERROR, "only mono or stereo is supported\n");
47         return AVERROR(EINVAL);
48     }
49 
50     shine_set_config_mpeg_defaults(&s->config.mpeg);
51     if (avctx->bit_rate)
52         s->config.mpeg.bitr = avctx->bit_rate / 1000;
53     s->config.mpeg.mode = avctx->channels == 2 ? STEREO : MONO;
54     s->config.wave.samplerate = avctx->sample_rate;
55     s->config.wave.channels   = avctx->channels == 2 ? PCM_STEREO : PCM_MONO;
56     if (shine_check_config(s->config.wave.samplerate, s->config.mpeg.bitr) < 0) {
57         av_log(avctx, AV_LOG_ERROR, "invalid configuration\n");
58         return AVERROR(EINVAL);
59     }
60     s->shine = shine_initialise(&s->config);
61     if (!s->shine)
62         return AVERROR(ENOMEM);
63     avctx->frame_size = shine_samples_per_pass(s->shine);
64     ff_af_queue_init(avctx, &s->afq);
65     return 0;
66 }
67 
libshine_encode_frame(AVCodecContext * avctx,AVPacket * avpkt,const AVFrame * frame,int * got_packet_ptr)68 static int libshine_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
69                                  const AVFrame *frame, int *got_packet_ptr)
70 {
71     SHINEContext *s = avctx->priv_data;
72     MPADecodeHeader hdr;
73     unsigned char *data;
74     int written;
75     int ret, len;
76 
77     if (frame)
78         data = shine_encode_buffer(s->shine, (int16_t **)frame->data, &written);
79     else
80         data = shine_flush(s->shine, &written);
81     if (written < 0)
82         return -1;
83     if (written > 0) {
84         if (s->buffer_index + written > BUFFER_SIZE) {
85             av_log(avctx, AV_LOG_ERROR, "internal buffer too small\n");
86             return AVERROR_BUG;
87         }
88         memcpy(s->buffer + s->buffer_index, data, written);
89         s->buffer_index += written;
90     }
91     if (frame) {
92         if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
93             return ret;
94     }
95 
96     if (s->buffer_index < 4 || !s->afq.frame_count)
97         return 0;
98     if (avpriv_mpegaudio_decode_header(&hdr, AV_RB32(s->buffer))) {
99         av_log(avctx, AV_LOG_ERROR, "free format output not supported\n");
100         return -1;
101     }
102 
103     len = hdr.frame_size;
104     if (len <= s->buffer_index) {
105         if ((ret = ff_alloc_packet2(avctx, avpkt, len, 0)))
106             return ret;
107         memcpy(avpkt->data, s->buffer, len);
108         s->buffer_index -= len;
109         memmove(s->buffer, s->buffer + len, s->buffer_index);
110 
111         ff_af_queue_remove(&s->afq, avctx->frame_size, &avpkt->pts,
112                            &avpkt->duration);
113 
114         avpkt->size = len;
115         *got_packet_ptr = 1;
116     }
117     return 0;
118 }
119 
libshine_encode_close(AVCodecContext * avctx)120 static av_cold int libshine_encode_close(AVCodecContext *avctx)
121 {
122     SHINEContext *s = avctx->priv_data;
123 
124     ff_af_queue_close(&s->afq);
125     shine_close(s->shine);
126     return 0;
127 }
128 
129 static const int libshine_sample_rates[] = {
130     44100, 48000, 32000, 0
131 };
132 
133 AVCodec ff_libshine_encoder = {
134     .name                  = "libshine",
135     .long_name             = NULL_IF_CONFIG_SMALL("libshine MP3 (MPEG audio layer 3)"),
136     .type                  = AVMEDIA_TYPE_AUDIO,
137     .id                    = AV_CODEC_ID_MP3,
138     .priv_data_size        = sizeof(SHINEContext),
139     .init                  = libshine_encode_init,
140     .encode2               = libshine_encode_frame,
141     .close                 = libshine_encode_close,
142     .capabilities          = AV_CODEC_CAP_DELAY,
143     .sample_fmts           = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16P,
144                                                             AV_SAMPLE_FMT_NONE },
145     .supported_samplerates = libshine_sample_rates,
146     .channel_layouts       = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
147                                                   AV_CH_LAYOUT_STEREO,
148                                                   0 },
149     .wrapper_name          = "libshine",
150 };
151