PeerStreamer

/*

 * Interface to libfaac for aac encoding

 * Copyright (c) 2002 Gildas Bazin <gbazin@netcourrier.com>

 *

 * 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

 * Interface to libfaac for aac encoding.

 */

#include "avcodec.h"

#include <faac.h>

typedef struct FaacAudioContext {

    faacEncHandle faac_handle;

} FaacAudioContext;

static av_cold int Faac_encode_init(AVCodecContext *avctx)

{

    FaacAudioContext *s = avctx->priv_data;

    faacEncConfigurationPtr faac_cfg;

    unsigned long samples_input, max_bytes_output;

    /* number of channels */

    if (avctx->channels < 1 || avctx->channels > 6) {

        av_log(avctx, AV_LOG_ERROR, "encoding %d channel(s) is not allowed\n", avctx->channels);

        return -1;

    }

    s->faac_handle = faacEncOpen(avctx->sample_rate,

                                 avctx->channels,

                                 &samples_input, &max_bytes_output);

    /* check faac version */

    faac_cfg = faacEncGetCurrentConfiguration(s->faac_handle);

    if (faac_cfg->version != FAAC_CFG_VERSION) {

        av_log(avctx, AV_LOG_ERROR, "wrong libfaac version (compiled for: %d, using %d)\n", FAAC_CFG_VERSION, faac_cfg->version);

        faacEncClose(s->faac_handle);

        return -1;

    }

    /* put the options in the configuration struct */

    switch(avctx->profile) {

        case FF_PROFILE_AAC_MAIN:

            faac_cfg->aacObjectType = MAIN;

            break;

        case FF_PROFILE_UNKNOWN:

        case FF_PROFILE_AAC_LOW:

            faac_cfg->aacObjectType = LOW;

            break;

        case FF_PROFILE_AAC_SSR:

            faac_cfg->aacObjectType = SSR;

            break;

        case FF_PROFILE_AAC_LTP:

            faac_cfg->aacObjectType = LTP;

            break;

        default:

            av_log(avctx, AV_LOG_ERROR, "invalid AAC profile\n");

            faacEncClose(s->faac_handle);

            return -1;

    }

    faac_cfg->mpegVersion = MPEG4;

    faac_cfg->useTns = 0;

    faac_cfg->allowMidside = 1;

    faac_cfg->bitRate = avctx->bit_rate / avctx->channels;

    faac_cfg->bandWidth = avctx->cutoff;

    if(avctx->flags & CODEC_FLAG_QSCALE) {

        faac_cfg->bitRate = 0;

        faac_cfg->quantqual = avctx->global_quality / FF_QP2LAMBDA;

    }

    faac_cfg->outputFormat = 1;

    faac_cfg->inputFormat = FAAC_INPUT_16BIT;

    avctx->frame_size = samples_input / avctx->channels;

    avctx->coded_frame= avcodec_alloc_frame();

    avctx->coded_frame->key_frame= 1;

    /* Set decoder specific info */

    avctx->extradata_size = 0;

    if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER) {

        unsigned char *buffer = NULL;

        unsigned long decoder_specific_info_size;

        if (!faacEncGetDecoderSpecificInfo(s->faac_handle, &buffer,

                                           &decoder_specific_info_size)) {

            avctx->extradata = av_malloc(decoder_specific_info_size + FF_INPUT_BUFFER_PADDING_SIZE);

            avctx->extradata_size = decoder_specific_info_size;

            memcpy(avctx->extradata, buffer, avctx->extradata_size);

            faac_cfg->outputFormat = 0;

        }

#undef free

        free(buffer);

#define free please_use_av_free

    }

    if (!faacEncSetConfiguration(s->faac_handle, faac_cfg)) {

        av_log(avctx, AV_LOG_ERROR, "libfaac doesn't support this output format!\n");

        return -1;

    }

    return 0;

}

static int Faac_encode_frame(AVCodecContext *avctx,

                             unsigned char *frame, int buf_size, void *data)

{

    FaacAudioContext *s = avctx->priv_data;

    int bytes_written;

    bytes_written = faacEncEncode(s->faac_handle,

                                  data,

                                  avctx->frame_size * avctx->channels,

                                  frame,

                                  buf_size);

    return bytes_written;

}

static av_cold int Faac_encode_close(AVCodecContext *avctx)

{

    FaacAudioContext *s = avctx->priv_data;

    av_freep(&avctx->coded_frame);

    av_freep(&avctx->extradata);

    faacEncClose(s->faac_handle);

    return 0;

}

static const AVProfile profiles[] = {

    { FF_PROFILE_AAC_MAIN, "Main" },

    { FF_PROFILE_AAC_LOW,  "LC"   },

    { FF_PROFILE_AAC_SSR,  "SSR"  },

    { FF_PROFILE_AAC_LTP,  "LTP"  },

    { FF_PROFILE_UNKNOWN },

};

AVCodec libfaac_encoder = {

    "libfaac",

    AVMEDIA_TYPE_AUDIO,

    CODEC_ID_AAC,

    sizeof(FaacAudioContext),

    Faac_encode_init,

    Faac_encode_frame,

    Faac_encode_close,

    .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},

    .long_name = NULL_IF_CONFIG_SMALL("libfaac AAC (Advanced Audio Codec)"),

    .profiles = NULL_IF_CONFIG_SMALL(profiles),

};