libspeexenc: add libspeex encoder

1 files changed, 324 insertions, 0 deletions

diff --git a/libavcodec/libspeexenc.c b/libavcodec/libspeexenc.c
new file mode 100644
index 0000000000..18f973f4fd
--- /dev/null
+++ b/libavcodec/libspeexenc.c
@@ -0,0 +1,324 @@
+/*
+ * Copyright (C) 2009 Justin Ruggles
+ * Copyright (c) 2009 Xuggle Incorporated
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 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.
+ */
+
+#include <speex/speex.h>
+#include <speex/speex_header.h>
+#include <speex/speex_stereo.h>
+#include "libavutil/mathematics.h"
+#include "libavutil/opt.h"
+#include "avcodec.h"
+#include "internal.h"
+
+typedef struct {
+    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 pkt_frame_count;        ///< frame count for the current packet
+    int lookahead;              ///< encoder delay
+    int sample_count;           ///< total sample count (used for pts)
+} 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);
+}
+
+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 & CODEC_FLAG_QSCALE) {
+        /* VBR */
+        s->header.vbr = 1;
+        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);
+    }
+
+    /* 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, &s->lookahead);
+    s->sample_count = -s->lookahead;
+
+    /* 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 and coded_frame */
+    avctx->extradata   = av_malloc(header_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    avctx->coded_frame = avcodec_alloc_frame();
+    if (!avctx->extradata || !avctx->coded_frame) {
+        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, uint8_t *frame, int buf_size,
+                        void *data)
+{
+    LibSpeexEncContext *s = avctx->priv_data;
+    int16_t *samples      = data;
+    int sample_count      = s->sample_count;
+
+    if (data) {
+        /* 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++;
+        s->sample_count += avctx->frame_size;
+    } 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;
+        avctx->coded_frame->pts =
+            av_rescale_q(sample_count, (AVRational){ 1, avctx->sample_rate },
+                         avctx->time_base);
+        if (buf_size > speex_bits_nbytes(&s->bits)) {
+            int ret = speex_bits_write(&s->bits, frame, buf_size);
+            speex_bits_reset(&s->bits);
+            return ret;
+        } else {
+            av_log(avctx, AV_LOG_ERROR, "output buffer too small");
+            return AVERROR(EINVAL);
+        }
+    }
+    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);
+
+    av_freep(&avctx->coded_frame);
+    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, { 0 }, 0,   1, AE },
+    { "cbr_quality",       "Set quality value (0 to 10) for CBR",       OFFSET(cbr_quality),       AV_OPT_TYPE_INT, { 8 }, 0,  10, AE },
+    { "frames_per_packet", "Number of frames to encode in each packet", OFFSET(frames_per_packet), AV_OPT_TYPE_INT, { 1 }, 1,   8, AE },
+    { NULL },
+};
+
+static const AVClass 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",
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = CODEC_ID_SPEEX,
+    .priv_data_size = sizeof(LibSpeexEncContext),
+    .init           = encode_init,
+    .encode         = encode_frame,
+    .close          = encode_close,
+    .capabilities   = CODEC_CAP_DELAY,
+    .sample_fmts    = (const enum SampleFormat[]){ AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
+    .long_name      = NULL_IF_CONFIG_SMALL("libspeex Speex"),
+    .priv_class     = &class,
+    .defaults       = defaults,
+};