0,0 → 1,368 |
/* |
* Copyright (C) 2009 Justin Ruggles |
* Copyright (c) 2009 Xuggle Incorporated |
* |
* This file is part of FFmpeg. |
* |
* FFmpeg is free software; you can redistribute it and/or |
* modify it under the terms of the GNU Lesser General Public |
* License as published by the Free Software Foundation; either |
* version 2.1 of the License, or (at your option) any later version. |
* |
* FFmpeg is distributed in the hope that it will be useful, |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
* Lesser General Public License for more details. |
* |
* You should have received a copy of the GNU Lesser General Public |
* License along with FFmpeg; if not, write to the Free Software |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
*/ |
|
/** |
* @file |
* libspeex Speex audio encoder |
* |
* Usage Guide |
* This explains the values that need to be set prior to initialization in |
* order to control various encoding parameters. |
* |
* Channels |
* Speex only supports mono or stereo, so avctx->channels must be set to |
* 1 or 2. |
* |
* Sample Rate / Encoding Mode |
* Speex has 3 modes, each of which uses a specific sample rate. |
* narrowband : 8 kHz |
* wideband : 16 kHz |
* ultra-wideband : 32 kHz |
* avctx->sample_rate must be set to one of these 3 values. This will be |
* used to set the encoding mode. |
* |
* Rate Control |
* VBR mode is turned on by setting AV_CODEC_FLAG_QSCALE in avctx->flags. |
* avctx->global_quality is used to set the encoding quality. |
* For CBR mode, avctx->bit_rate can be used to set the constant bitrate. |
* Alternatively, the 'cbr_quality' option can be set from 0 to 10 to set |
* a constant bitrate based on quality. |
* For ABR mode, set avctx->bit_rate and set the 'abr' option to 1. |
* Approx. Bitrate Range: |
* narrowband : 2400 - 25600 bps |
* wideband : 4000 - 43200 bps |
* ultra-wideband : 4400 - 45200 bps |
* |
* Complexity |
* Encoding complexity is controlled by setting avctx->compression_level. |
* The valid range is 0 to 10. A higher setting gives generally better |
* quality at the expense of encoding speed. This does not affect the |
* bit rate. |
* |
* Frames-per-Packet |
* The encoder defaults to using 1 frame-per-packet. However, it is |
* sometimes desirable to use multiple frames-per-packet to reduce the |
* amount of container overhead. This can be done by setting the |
* 'frames_per_packet' option to a value 1 to 8. |
* |
* |
* Optional features |
* Speex encoder supports several optional features, which can be useful |
* for some conditions. |
* |
* Voice Activity Detection |
* When enabled, voice activity detection detects whether the audio |
* being encoded is speech or silence/background noise. VAD is always |
* implicitly activated when encoding in VBR, so the option is only useful |
* in non-VBR operation. In this case, Speex detects non-speech periods and |
* encodes them with just enough bits to reproduce the background noise. |
* |
* Discontinuous Transmission (DTX) |
* DTX is an addition to VAD/VBR operation, that makes it possible to stop transmitting |
* completely when the background noise is stationary. |
* In file-based operation only 5 bits are used for such frames. |
*/ |
|
#include <speex/speex.h> |
#include <speex/speex_header.h> |
#include <speex/speex_stereo.h> |
|
#include "libavutil/channel_layout.h" |
#include "libavutil/common.h" |
#include "libavutil/opt.h" |
#include "avcodec.h" |
#include "internal.h" |
#include "audio_frame_queue.h" |
|
/* TODO: Think about converting abr, vad, dtx and such flags to a bit field */ |
typedef struct LibSpeexEncContext { |
AVClass *class; ///< AVClass for private options |
SpeexBits bits; ///< libspeex bitwriter context |
SpeexHeader header; ///< libspeex header struct |
void *enc_state; ///< libspeex encoder state |
int frames_per_packet; ///< number of frames to encode in each packet |
float vbr_quality; ///< VBR quality 0.0 to 10.0 |
int cbr_quality; ///< CBR quality 0 to 10 |
int abr; ///< flag to enable ABR |
int vad; ///< flag to enable VAD |
int dtx; ///< flag to enable DTX |
int pkt_frame_count; ///< frame count for the current packet |
AudioFrameQueue afq; ///< frame queue |
} LibSpeexEncContext; |
|
static av_cold void print_enc_params(AVCodecContext *avctx, |
LibSpeexEncContext *s) |
{ |
const char *mode_str = "unknown"; |
|
av_log(avctx, AV_LOG_DEBUG, "channels: %d\n", avctx->channels); |
switch (s->header.mode) { |
case SPEEX_MODEID_NB: mode_str = "narrowband"; break; |
case SPEEX_MODEID_WB: mode_str = "wideband"; break; |
case SPEEX_MODEID_UWB: mode_str = "ultra-wideband"; break; |
} |
av_log(avctx, AV_LOG_DEBUG, "mode: %s\n", mode_str); |
if (s->header.vbr) { |
av_log(avctx, AV_LOG_DEBUG, "rate control: VBR\n"); |
av_log(avctx, AV_LOG_DEBUG, " quality: %f\n", s->vbr_quality); |
} else if (s->abr) { |
av_log(avctx, AV_LOG_DEBUG, "rate control: ABR\n"); |
av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); |
} else { |
av_log(avctx, AV_LOG_DEBUG, "rate control: CBR\n"); |
av_log(avctx, AV_LOG_DEBUG, " bitrate: %d bps\n", avctx->bit_rate); |
} |
av_log(avctx, AV_LOG_DEBUG, "complexity: %d\n", |
avctx->compression_level); |
av_log(avctx, AV_LOG_DEBUG, "frame size: %d samples\n", |
avctx->frame_size); |
av_log(avctx, AV_LOG_DEBUG, "frames per packet: %d\n", |
s->frames_per_packet); |
av_log(avctx, AV_LOG_DEBUG, "packet size: %d\n", |
avctx->frame_size * s->frames_per_packet); |
av_log(avctx, AV_LOG_DEBUG, "voice activity detection: %d\n", s->vad); |
av_log(avctx, AV_LOG_DEBUG, "discontinuous transmission: %d\n", s->dtx); |
} |
|
static av_cold int encode_init(AVCodecContext *avctx) |
{ |
LibSpeexEncContext *s = avctx->priv_data; |
const SpeexMode *mode; |
uint8_t *header_data; |
int header_size; |
int32_t complexity; |
|
/* channels */ |
if (avctx->channels < 1 || avctx->channels > 2) { |
av_log(avctx, AV_LOG_ERROR, "Invalid channels (%d). Only stereo and " |
"mono are supported\n", avctx->channels); |
return AVERROR(EINVAL); |
} |
|
/* sample rate and encoding mode */ |
switch (avctx->sample_rate) { |
case 8000: mode = &speex_nb_mode; break; |
case 16000: mode = &speex_wb_mode; break; |
case 32000: mode = &speex_uwb_mode; break; |
default: |
av_log(avctx, AV_LOG_ERROR, "Sample rate of %d Hz is not supported. " |
"Resample to 8, 16, or 32 kHz.\n", avctx->sample_rate); |
return AVERROR(EINVAL); |
} |
|
/* initialize libspeex */ |
s->enc_state = speex_encoder_init(mode); |
if (!s->enc_state) { |
av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex\n"); |
return -1; |
} |
speex_init_header(&s->header, avctx->sample_rate, avctx->channels, mode); |
|
/* rate control method and parameters */ |
if (avctx->flags & AV_CODEC_FLAG_QSCALE) { |
/* VBR */ |
s->header.vbr = 1; |
s->vad = 1; /* VAD is always implicitly activated for VBR */ |
speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR, &s->header.vbr); |
s->vbr_quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA, |
0.0f, 10.0f); |
speex_encoder_ctl(s->enc_state, SPEEX_SET_VBR_QUALITY, &s->vbr_quality); |
} else { |
s->header.bitrate = avctx->bit_rate; |
if (avctx->bit_rate > 0) { |
/* CBR or ABR by bitrate */ |
if (s->abr) { |
speex_encoder_ctl(s->enc_state, SPEEX_SET_ABR, |
&s->header.bitrate); |
speex_encoder_ctl(s->enc_state, SPEEX_GET_ABR, |
&s->header.bitrate); |
} else { |
speex_encoder_ctl(s->enc_state, SPEEX_SET_BITRATE, |
&s->header.bitrate); |
speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, |
&s->header.bitrate); |
} |
} else { |
/* CBR by quality */ |
speex_encoder_ctl(s->enc_state, SPEEX_SET_QUALITY, |
&s->cbr_quality); |
speex_encoder_ctl(s->enc_state, SPEEX_GET_BITRATE, |
&s->header.bitrate); |
} |
/* stereo side information adds about 800 bps to the base bitrate */ |
/* TODO: this should be calculated exactly */ |
avctx->bit_rate = s->header.bitrate + (avctx->channels == 2 ? 800 : 0); |
} |
|
/* VAD is activated with VBR or can be turned on by itself */ |
if (s->vad) |
speex_encoder_ctl(s->enc_state, SPEEX_SET_VAD, &s->vad); |
|
/* Activiting Discontinuous Transmission */ |
if (s->dtx) { |
speex_encoder_ctl(s->enc_state, SPEEX_SET_DTX, &s->dtx); |
if (!(s->abr || s->vad || s->header.vbr)) |
av_log(avctx, AV_LOG_WARNING, "DTX is not much of use without ABR, VAD or VBR\n"); |
} |
|
/* set encoding complexity */ |
if (avctx->compression_level > FF_COMPRESSION_DEFAULT) { |
complexity = av_clip(avctx->compression_level, 0, 10); |
speex_encoder_ctl(s->enc_state, SPEEX_SET_COMPLEXITY, &complexity); |
} |
speex_encoder_ctl(s->enc_state, SPEEX_GET_COMPLEXITY, &complexity); |
avctx->compression_level = complexity; |
|
/* set packet size */ |
avctx->frame_size = s->header.frame_size; |
s->header.frames_per_packet = s->frames_per_packet; |
|
/* set encoding delay */ |
speex_encoder_ctl(s->enc_state, SPEEX_GET_LOOKAHEAD, &avctx->initial_padding); |
ff_af_queue_init(avctx, &s->afq); |
|
/* create header packet bytes from header struct */ |
/* note: libspeex allocates the memory for header_data, which is freed |
below with speex_header_free() */ |
header_data = speex_header_to_packet(&s->header, &header_size); |
|
/* allocate extradata */ |
avctx->extradata = av_malloc(header_size + AV_INPUT_BUFFER_PADDING_SIZE); |
if (!avctx->extradata) { |
speex_header_free(header_data); |
speex_encoder_destroy(s->enc_state); |
av_log(avctx, AV_LOG_ERROR, "memory allocation error\n"); |
return AVERROR(ENOMEM); |
} |
|
/* copy header packet to extradata */ |
memcpy(avctx->extradata, header_data, header_size); |
avctx->extradata_size = header_size; |
speex_header_free(header_data); |
|
/* init libspeex bitwriter */ |
speex_bits_init(&s->bits); |
|
print_enc_params(avctx, s); |
return 0; |
} |
|
static int encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
const AVFrame *frame, int *got_packet_ptr) |
{ |
LibSpeexEncContext *s = avctx->priv_data; |
int16_t *samples = frame ? (int16_t *)frame->data[0] : NULL; |
int ret; |
|
if (samples) { |
/* encode Speex frame */ |
if (avctx->channels == 2) |
speex_encode_stereo_int(samples, s->header.frame_size, &s->bits); |
speex_encode_int(s->enc_state, samples, &s->bits); |
s->pkt_frame_count++; |
if ((ret = ff_af_queue_add(&s->afq, frame)) < 0) |
return ret; |
} else { |
/* handle end-of-stream */ |
if (!s->pkt_frame_count) |
return 0; |
/* add extra terminator codes for unused frames in last packet */ |
while (s->pkt_frame_count < s->frames_per_packet) { |
speex_bits_pack(&s->bits, 15, 5); |
s->pkt_frame_count++; |
} |
} |
|
/* write output if all frames for the packet have been encoded */ |
if (s->pkt_frame_count == s->frames_per_packet) { |
s->pkt_frame_count = 0; |
if ((ret = ff_alloc_packet2(avctx, avpkt, speex_bits_nbytes(&s->bits), 0)) < 0) |
return ret; |
ret = speex_bits_write(&s->bits, avpkt->data, avpkt->size); |
speex_bits_reset(&s->bits); |
|
/* Get the next frame pts/duration */ |
ff_af_queue_remove(&s->afq, s->frames_per_packet * avctx->frame_size, |
&avpkt->pts, &avpkt->duration); |
|
avpkt->size = ret; |
*got_packet_ptr = 1; |
return 0; |
} |
return 0; |
} |
|
static av_cold int encode_close(AVCodecContext *avctx) |
{ |
LibSpeexEncContext *s = avctx->priv_data; |
|
speex_bits_destroy(&s->bits); |
speex_encoder_destroy(s->enc_state); |
|
ff_af_queue_close(&s->afq); |
av_freep(&avctx->extradata); |
|
return 0; |
} |
|
#define OFFSET(x) offsetof(LibSpeexEncContext, x) |
#define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM |
static const AVOption options[] = { |
{ "abr", "Use average bit rate", OFFSET(abr), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, |
{ "cbr_quality", "Set quality value (0 to 10) for CBR", OFFSET(cbr_quality), AV_OPT_TYPE_INT, { .i64 = 8 }, 0, 10, AE }, |
{ "frames_per_packet", "Number of frames to encode in each packet", OFFSET(frames_per_packet), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 8, AE }, |
{ "vad", "Voice Activity Detection", OFFSET(vad), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, |
{ "dtx", "Discontinuous Transmission", OFFSET(dtx), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AE }, |
{ NULL }, |
}; |
|
static const AVClass speex_class = { |
.class_name = "libspeex", |
.item_name = av_default_item_name, |
.option = options, |
.version = LIBAVUTIL_VERSION_INT, |
}; |
|
static const AVCodecDefault defaults[] = { |
{ "b", "0" }, |
{ "compression_level", "3" }, |
{ NULL }, |
}; |
|
AVCodec ff_libspeex_encoder = { |
.name = "libspeex", |
.long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"), |
.type = AVMEDIA_TYPE_AUDIO, |
.id = AV_CODEC_ID_SPEEX, |
.priv_data_size = sizeof(LibSpeexEncContext), |
.init = encode_init, |
.encode2 = encode_frame, |
.close = encode_close, |
.capabilities = AV_CODEC_CAP_DELAY, |
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
AV_SAMPLE_FMT_NONE }, |
.channel_layouts = (const uint64_t[]){ AV_CH_LAYOUT_MONO, |
AV_CH_LAYOUT_STEREO, |
0 }, |
.supported_samplerates = (const int[]){ 8000, 16000, 32000, 0 }, |
.priv_class = &speex_class, |
.defaults = defaults, |
}; |