FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
libfaac.c
Go to the documentation of this file.
1 /*
2  * Interface to libfaac for aac encoding
3  * Copyright (c) 2002 Gildas Bazin <gbazin@netcourrier.com>
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 /**
23  * @file
24  * Interface to libfaac for aac encoding.
25  */
26 
27 #include <faac.h>
28 
30 #include "libavutil/common.h"
31 #include "avcodec.h"
32 #include "audio_frame_queue.h"
33 #include "internal.h"
34 
35 
36 /* libfaac has an encoder delay of 1024 samples */
37 #define FAAC_DELAY_SAMPLES 1024
38 
39 typedef struct FaacAudioContext {
40  faacEncHandle faac_handle;
43 
45 {
46  FaacAudioContext *s = avctx->priv_data;
47 
48  av_freep(&avctx->extradata);
50 
51  if (s->faac_handle)
52  faacEncClose(s->faac_handle);
53 
54  return 0;
55 }
56 
57 static const int channel_maps[][6] = {
58  { 2, 0, 1 }, //< C L R
59  { 2, 0, 1, 3 }, //< C L R Cs
60  { 2, 0, 1, 3, 4 }, //< C L R Ls Rs
61  { 2, 0, 1, 4, 5, 3 }, //< C L R Ls Rs LFE
62 };
63 
65 {
66  FaacAudioContext *s = avctx->priv_data;
67  faacEncConfigurationPtr faac_cfg;
68  unsigned long samples_input, max_bytes_output;
69  int ret;
70 
71  /* number of channels */
72  if (avctx->channels < 1 || avctx->channels > 6) {
73  av_log(avctx, AV_LOG_ERROR, "encoding %d channel(s) is not allowed\n", avctx->channels);
74  ret = AVERROR(EINVAL);
75  goto error;
76  }
77 
78  s->faac_handle = faacEncOpen(avctx->sample_rate,
79  avctx->channels,
80  &samples_input, &max_bytes_output);
81  if (!s->faac_handle) {
82  av_log(avctx, AV_LOG_ERROR, "error in faacEncOpen()\n");
83  ret = AVERROR_UNKNOWN;
84  goto error;
85  }
86 
87  /* check faac version */
88  faac_cfg = faacEncGetCurrentConfiguration(s->faac_handle);
89  if (faac_cfg->version != FAAC_CFG_VERSION) {
90  av_log(avctx, AV_LOG_ERROR, "wrong libfaac version (compiled for: %d, using %d)\n", FAAC_CFG_VERSION, faac_cfg->version);
91  ret = AVERROR(EINVAL);
92  goto error;
93  }
94 
95  /* put the options in the configuration struct */
96  switch(avctx->profile) {
98  faac_cfg->aacObjectType = MAIN;
99  break;
100  case FF_PROFILE_UNKNOWN:
101  case FF_PROFILE_AAC_LOW:
102  faac_cfg->aacObjectType = LOW;
103  break;
104  case FF_PROFILE_AAC_SSR:
105  faac_cfg->aacObjectType = SSR;
106  break;
107  case FF_PROFILE_AAC_LTP:
108  faac_cfg->aacObjectType = LTP;
109  break;
110  default:
111  av_log(avctx, AV_LOG_ERROR, "invalid AAC profile\n");
112  ret = AVERROR(EINVAL);
113  goto error;
114  }
115  faac_cfg->mpegVersion = MPEG4;
116  faac_cfg->useTns = 0;
117  faac_cfg->allowMidside = 1;
118  faac_cfg->bitRate = avctx->bit_rate / avctx->channels;
119  faac_cfg->bandWidth = avctx->cutoff;
120  if(avctx->flags & CODEC_FLAG_QSCALE) {
121  faac_cfg->bitRate = 0;
122  faac_cfg->quantqual = avctx->global_quality / FF_QP2LAMBDA;
123  }
124  faac_cfg->outputFormat = 1;
125  faac_cfg->inputFormat = FAAC_INPUT_16BIT;
126  if (avctx->channels > 2)
127  memcpy(faac_cfg->channel_map, channel_maps[avctx->channels-3],
128  avctx->channels * sizeof(int));
129 
130  avctx->frame_size = samples_input / avctx->channels;
131 
132  /* Set decoder specific info */
133  avctx->extradata_size = 0;
134  if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER) {
135 
136  unsigned char *buffer = NULL;
137  unsigned long decoder_specific_info_size;
138 
139  if (!faacEncGetDecoderSpecificInfo(s->faac_handle, &buffer,
140  &decoder_specific_info_size)) {
141  avctx->extradata = av_malloc(decoder_specific_info_size + FF_INPUT_BUFFER_PADDING_SIZE);
142  if (!avctx->extradata) {
143  ret = AVERROR(ENOMEM);
144  goto error;
145  }
146  avctx->extradata_size = decoder_specific_info_size;
147  memcpy(avctx->extradata, buffer, avctx->extradata_size);
148  faac_cfg->outputFormat = 0;
149  }
150  free(buffer);
151  }
152 
153  if (!faacEncSetConfiguration(s->faac_handle, faac_cfg)) {
154  int i;
155  for (i = avctx->bit_rate/1000; i ; i--) {
156  faac_cfg->bitRate = 1000*i / avctx->channels;
157  if (faacEncSetConfiguration(s->faac_handle, faac_cfg))
158  break;
159  }
160  if (!i) {
161  av_log(avctx, AV_LOG_ERROR, "libfaac doesn't support this output format!\n");
162  ret = AVERROR(EINVAL);
163  goto error;
164  } else {
165  avctx->bit_rate = 1000*i;
166  av_log(avctx, AV_LOG_WARNING, "libfaac doesn't support the specified bitrate, using %dkbit/s instead\n", i);
167  }
168  }
169 
170  avctx->delay = FAAC_DELAY_SAMPLES;
171  ff_af_queue_init(avctx, &s->afq);
172 
173  return 0;
174 error:
175  Faac_encode_close(avctx);
176  return ret;
177 }
178 
179 static int Faac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
180  const AVFrame *frame, int *got_packet_ptr)
181 {
182  FaacAudioContext *s = avctx->priv_data;
183  int bytes_written, ret;
184  int num_samples = frame ? frame->nb_samples : 0;
185  void *samples = frame ? frame->data[0] : NULL;
186 
187  if ((ret = ff_alloc_packet2(avctx, avpkt, (7 + 768) * avctx->channels)) < 0)
188  return ret;
189 
190  bytes_written = faacEncEncode(s->faac_handle, samples,
191  num_samples * avctx->channels,
192  avpkt->data, avpkt->size);
193  if (bytes_written < 0) {
194  av_log(avctx, AV_LOG_ERROR, "faacEncEncode() error\n");
195  return bytes_written;
196  }
197 
198  /* add current frame to the queue */
199  if (frame) {
200  if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
201  return ret;
202  }
203 
204  if (!bytes_written)
205  return 0;
206 
207  /* Get the next frame pts/duration */
208  ff_af_queue_remove(&s->afq, avctx->frame_size, &avpkt->pts,
209  &avpkt->duration);
210 
211  avpkt->size = bytes_written;
212  *got_packet_ptr = 1;
213  return 0;
214 }
215 
216 static const AVProfile profiles[] = {
217  { FF_PROFILE_AAC_MAIN, "Main" },
218  { FF_PROFILE_AAC_LOW, "LC" },
219  { FF_PROFILE_AAC_SSR, "SSR" },
220  { FF_PROFILE_AAC_LTP, "LTP" },
221  { FF_PROFILE_UNKNOWN },
222 };
223 
224 static const uint64_t faac_channel_layouts[] = {
231  0
232 };
233 
235  .name = "libfaac",
236  .type = AVMEDIA_TYPE_AUDIO,
237  .id = AV_CODEC_ID_AAC,
238  .priv_data_size = sizeof(FaacAudioContext),
240  .encode2 = Faac_encode_frame,
243  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
245  .long_name = NULL_IF_CONFIG_SMALL("libfaac AAC (Advanced Audio Coding)"),
246  .profiles = NULL_IF_CONFIG_SMALL(profiles),
247  .channel_layouts = faac_channel_layouts,
248 };