[deb_ffmpeg.git] / ffmpeg / libavformat / mp3enc.c

/*
 * MP3 muxer
 * Copyright (c) 2003 Fabrice Bellard
 *
 * 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
 */

#include "avformat.h"
#include "avio_internal.h"
#include "id3v1.h"
#include "id3v2.h"
#include "rawenc.h"
#include "libavutil/avstring.h"
#include "libavcodec/mpegaudio.h"
#include "libavcodec/mpegaudiodata.h"
#include "libavcodec/mpegaudiodecheader.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavutil/avassert.h"

static int id3v1_set_string(AVFormatContext *s, const char *key,
                            uint8_t *buf, int buf_size)
{
    AVDictionaryEntry *tag;
    if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
        av_strlcpy(buf, tag->value, buf_size);
    return !!tag;
}

static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
{
    AVDictionaryEntry *tag;
    int i, count = 0;

    memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
    buf[0] = 'T';
    buf[1] = 'A';
    buf[2] = 'G';
    /* we knowingly overspecify each tag length by one byte to compensate for the mandatory null byte added by av_strlcpy */
    count += id3v1_set_string(s, "TIT2",    buf +  3, 30 + 1);       //title
    count += id3v1_set_string(s, "TPE1",    buf + 33, 30 + 1);       //author|artist
    count += id3v1_set_string(s, "TALB",    buf + 63, 30 + 1);       //album
    count += id3v1_set_string(s, "TDRL",    buf + 93,  4 + 1);       //date
    count += id3v1_set_string(s, "comment", buf + 97, 30 + 1);
    if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
        buf[125] = 0;
        buf[126] = atoi(tag->value);
        count++;
    }
    buf[127] = 0xFF; /* default to unknown genre */
    if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
        for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
            if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
                buf[127] = i;
                count++;
                break;
            }
        }
    }
    return count;
}

#define XING_NUM_BAGS 400
#define XING_TOC_SIZE 100
// maximum size of the xing frame: offset/Xing/flags/frames/size/TOC
#define XING_MAX_SIZE (32 + 4 + 4 + 4 + 4 + XING_TOC_SIZE)

typedef struct MP3Context {
    const AVClass *class;
    ID3v2EncContext id3;
    int id3v2_version;
    int write_id3v1;
    int write_xing;

    /* xing header */
    int64_t xing_offset;
    int32_t frames;
    int32_t size;
    uint32_t want;
    uint32_t seen;
    uint32_t pos;
    uint64_t bag[XING_NUM_BAGS];
    int initial_bitrate;
    int has_variable_bitrate;

    /* index of the audio stream */
    int audio_stream_idx;
    /* number of attached pictures we still need to write */
    int pics_to_write;

    /* audio packets are queued here until we get all the attached pictures */
    AVPacketList *queue, *queue_end;
} MP3Context;

static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};

/*
 * Write an empty XING header and initialize respective data.
 */
static int mp3_write_xing(AVFormatContext *s)
{
    MP3Context       *mp3 = s->priv_data;
    AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec;
    int32_t          header;
    MPADecodeHeader  mpah;
    int srate_idx, i, channels;
    int bitrate_idx;
    int best_bitrate_idx = -1;
    int best_bitrate_error = INT_MAX;
    int xing_offset;
    int ver = 0;
    int bytes_needed;
    const char *vendor = (s->flags & AVFMT_FLAG_BITEXACT) ? "Lavf" : LIBAVFORMAT_IDENT;

    if (!s->pb->seekable || !mp3->write_xing)
        return 0;

    for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
        const uint16_t base_freq = avpriv_mpa_freq_tab[i];

        if      (codec->sample_rate == base_freq)     ver = 0x3; // MPEG 1
        else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
        else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
        else continue;

        srate_idx = i;
        break;
    }
    if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
        av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing header.\n");
        return -1;
    }

    switch (codec->channels) {
    case 1:  channels = MPA_MONO;                                          break;
    case 2:  channels = MPA_STEREO;                                        break;
    default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
                    "not writing Xing header.\n");
             return -1;
    }

    /* dummy MPEG audio header */
    header  =  0xffU                                 << 24; // sync
    header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
    header |= (srate_idx << 2) << 8;
    header |= channels << 6;

    for (bitrate_idx = 1; bitrate_idx < 15; bitrate_idx++) {
        int bit_rate = 1000 * avpriv_mpa_bitrate_tab[ver != 3][3 - 1][bitrate_idx];
        int error    = FFABS(bit_rate - codec->bit_rate);

        if (error < best_bitrate_error) {
            best_bitrate_error = error;
            best_bitrate_idx   = bitrate_idx;
        }
    }
    av_assert0(best_bitrate_idx >= 0);

    for (bitrate_idx = best_bitrate_idx; ; bitrate_idx++) {
        int32_t mask = bitrate_idx << (4 + 8);
        if (15 == bitrate_idx)
            return -1;
        header |= mask;

        avpriv_mpegaudio_decode_header(&mpah, header);
        xing_offset=xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1];
        bytes_needed = 4              // header
               + xing_offset
               + 4              // xing tag
               + 4              // frames/size/toc flags
               + 4              // frames
               + 4              // size
               + XING_TOC_SIZE   // toc
               + 24
               ;

        if (bytes_needed <= mpah.frame_size)
            break;

        header &= ~mask;
    }

    avio_wb32(s->pb, header);

    ffio_fill(s->pb, 0, xing_offset);
    mp3->xing_offset = avio_tell(s->pb);
    ffio_wfourcc(s->pb, "Xing");
    avio_wb32(s->pb, 0x01 | 0x02 | 0x04);  // frames / size / TOC

    mp3->size = mpah.frame_size;
    mp3->want=1;
    mp3->seen=0;
    mp3->pos=0;

    avio_wb32(s->pb, 0);  // frames
    avio_wb32(s->pb, 0);  // size

    // toc
    for (i = 0; i < XING_TOC_SIZE; ++i)
        avio_w8(s->pb, (uint8_t)(255 * i / XING_TOC_SIZE));

    for (i = 0; i < strlen(vendor); ++i)
        avio_w8(s->pb, vendor[i]);
    for (; i < 21; ++i)
        avio_w8(s->pb, 0);
    avio_wb24(s->pb, FFMAX(codec->delay - 528 - 1, 0)<<12);

    ffio_fill(s->pb, 0, mpah.frame_size - bytes_needed);

    return 0;
}

/*
 * Add a frame to XING data.
 * Following lame's "VbrTag.c".
 */
static void mp3_xing_add_frame(MP3Context *mp3, AVPacket *pkt)
{
    int i;

    mp3->frames++;
    mp3->seen++;
    mp3->size += pkt->size;

    if (mp3->want == mp3->seen) {
        mp3->bag[mp3->pos] = mp3->size;

        if (XING_NUM_BAGS == ++mp3->pos) {
            /* shrink table to half size by throwing away each second bag. */
            for (i = 1; i < XING_NUM_BAGS; i += 2)
                mp3->bag[i >> 1] = mp3->bag[i];

            /* double wanted amount per bag. */
            mp3->want *= 2;
            /* adjust current position to half of table size. */
            mp3->pos = XING_NUM_BAGS / 2;
        }

        mp3->seen = 0;
    }
}

static int mp3_write_audio_packet(AVFormatContext *s, AVPacket *pkt)
{
    MP3Context  *mp3 = s->priv_data;

    if (pkt->data && pkt->size >= 4) {
        MPADecodeHeader mpah;
        int av_unused base;
        uint32_t h;

        h = AV_RB32(pkt->data);
        if (ff_mpa_check_header(h) == 0) {
            avpriv_mpegaudio_decode_header(&mpah, h);
            if (!mp3->initial_bitrate)
                mp3->initial_bitrate = mpah.bit_rate;
            if ((mpah.bit_rate == 0) || (mp3->initial_bitrate != mpah.bit_rate))
                mp3->has_variable_bitrate = 1;
        } else {
            av_log(s, AV_LOG_WARNING, "Audio packet of size %d (starting with %08X...) "
                   "is invalid, writing it anyway.\n", pkt->size, h);
        }

#ifdef FILTER_VBR_HEADERS
        /* filter out XING and INFO headers. */
        base = 4 + xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1];

        if (base + 4 <= pkt->size) {
            uint32_t v = AV_RB32(pkt->data + base);

            if (MKBETAG('X','i','n','g') == v || MKBETAG('I','n','f','o') == v)
                return 0;
        }

        /* filter out VBRI headers. */
        base = 4 + 32;

        if (base + 4 <= pkt->size && MKBETAG('V','B','R','I') == AV_RB32(pkt->data + base))
            return 0;
#endif

        if (mp3->xing_offset)
            mp3_xing_add_frame(mp3, pkt);
    }

    return ff_raw_write_packet(s, pkt);
}

static int mp3_queue_flush(AVFormatContext *s)
{
    MP3Context *mp3 = s->priv_data;
    AVPacketList *pktl;
    int ret = 0, write = 1;

    ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
    mp3_write_xing(s);

    while ((pktl = mp3->queue)) {
        if (write && (ret = mp3_write_audio_packet(s, &pktl->pkt)) < 0)
            write = 0;
        av_free_packet(&pktl->pkt);
        mp3->queue = pktl->next;
        av_freep(&pktl);
    }
    mp3->queue_end = NULL;
    return ret;
}

static void mp3_update_xing(AVFormatContext *s)
{
    MP3Context  *mp3 = s->priv_data;
    int i;

    /* replace "Xing" identification string with "Info" for CBR files. */
    if (!mp3->has_variable_bitrate) {
        avio_seek(s->pb, mp3->xing_offset, SEEK_SET);
        ffio_wfourcc(s->pb, "Info");
    }

    avio_seek(s->pb, mp3->xing_offset + 8, SEEK_SET);
    avio_wb32(s->pb, mp3->frames);
    avio_wb32(s->pb, mp3->size);

    avio_w8(s->pb, 0);  // first toc entry has to be zero.

    for (i = 1; i < XING_TOC_SIZE; ++i) {
        int j = i * mp3->pos / XING_TOC_SIZE;
        int seek_point = 256LL * mp3->bag[j] / mp3->size;
        avio_w8(s->pb, FFMIN(seek_point, 255));
    }

    avio_seek(s->pb, 0, SEEK_END);
}

static int mp3_write_trailer(struct AVFormatContext *s)
{
    uint8_t buf[ID3v1_TAG_SIZE];
    MP3Context *mp3 = s->priv_data;

    if (mp3->pics_to_write) {
        av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
               "attached pictures.\n");
        mp3_queue_flush(s);
    }

    /* write the id3v1 tag */
    if (mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
        avio_write(s->pb, buf, ID3v1_TAG_SIZE);
    }

    if (mp3->xing_offset)
        mp3_update_xing(s);

    return 0;
}

static int query_codec(enum AVCodecID id, int std_compliance)
{
    const CodecMime *cm= ff_id3v2_mime_tags;
    while(cm->id != AV_CODEC_ID_NONE) {
        if(id == cm->id)
            return MKTAG('A', 'P', 'I', 'C');
        cm++;
    }
    return -1;
}

#if CONFIG_MP2_MUXER
AVOutputFormat ff_mp2_muxer = {
    .name              = "mp2",
    .long_name         = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
    .mime_type         = "audio/mpeg",
    .extensions        = "mp2,m2a,mpa",
    .audio_codec       = AV_CODEC_ID_MP2,
    .video_codec       = AV_CODEC_ID_NONE,
    .write_packet      = ff_raw_write_packet,
    .flags             = AVFMT_NOTIMESTAMPS,
};
#endif

#if CONFIG_MP3_MUXER

static const AVOption options[] = {
    { "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
      offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 0, 4, AV_OPT_FLAG_ENCODING_PARAM},
    { "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
      offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
    { "write_xing",  "Write the Xing header containing file duration.",
      offsetof(MP3Context, write_xing),  AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
    { NULL },
};

static const AVClass mp3_muxer_class = {
    .class_name     = "MP3 muxer",
    .item_name      = av_default_item_name,
    .option         = options,
    .version        = LIBAVUTIL_VERSION_INT,
};

static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    MP3Context *mp3 = s->priv_data;

    if (pkt->stream_index == mp3->audio_stream_idx) {
        if (mp3->pics_to_write) {
            /* buffer audio packets until we get all the pictures */
            AVPacketList *pktl = av_mallocz(sizeof(*pktl));
            int ret;
            if (!pktl) {
                av_log(s, AV_LOG_WARNING, "Not enough memory to buffer audio. Skipping picture streams\n");
                mp3->pics_to_write = 0;
                mp3_queue_flush(s);
                return mp3_write_audio_packet(s, pkt);
            }

            ret = av_copy_packet(&pktl->pkt, pkt);
            if (ret < 0) {
                av_freep(&pktl);
                return ret;
            }

            if (mp3->queue_end)
                mp3->queue_end->next = pktl;
            else
                mp3->queue = pktl;
            mp3->queue_end = pktl;
        } else
            return mp3_write_audio_packet(s, pkt);
    } else {
        int ret;

        /* warn only once for each stream */
        if (s->streams[pkt->stream_index]->nb_frames == 1) {
            av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
                   " ignoring.\n", pkt->stream_index);
        }
        if (!mp3->pics_to_write || s->streams[pkt->stream_index]->nb_frames >= 1)
            return 0;

        if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
            return ret;
        mp3->pics_to_write--;

        /* flush the buffered audio packets */
        if (!mp3->pics_to_write &&
            (ret = mp3_queue_flush(s)) < 0)
            return ret;
    }

    return 0;
}

/**
 * Write an ID3v2 header at beginning of stream
 */

static int mp3_write_header(struct AVFormatContext *s)
{
    MP3Context  *mp3 = s->priv_data;
    int ret, i;

    if (mp3->id3v2_version      &&
        mp3->id3v2_version != 3 &&
        mp3->id3v2_version != 4) {
        av_log(s, AV_LOG_ERROR, "Invalid ID3v2 version requested: %d. Only "
               "3, 4 or 0 (disabled) are allowed.\n", mp3->id3v2_version);
        return AVERROR(EINVAL);
    }

    /* check the streams -- we want exactly one audio and arbitrary number of
     * video (attached pictures) */
    mp3->audio_stream_idx = -1;
    for (i = 0; i < s->nb_streams; i++) {
        AVStream *st = s->streams[i];
        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (mp3->audio_stream_idx >= 0 || st->codec->codec_id != AV_CODEC_ID_MP3) {
                av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
                       "audio stream is required.\n");
                return AVERROR(EINVAL);
            }
            mp3->audio_stream_idx = i;
        } else if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) {
            av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
            return AVERROR(EINVAL);
        }
    }
    if (mp3->audio_stream_idx < 0) {
        av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
        return AVERROR(EINVAL);
    }
    mp3->pics_to_write = s->nb_streams - 1;

    if (mp3->pics_to_write && !mp3->id3v2_version) {
        av_log(s, AV_LOG_ERROR, "Attached pictures were requested, but the "
               "ID3v2 header is disabled.\n");
        return AVERROR(EINVAL);
    }

    if (mp3->id3v2_version) {
        ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
        ret = ff_id3v2_write_metadata(s, &mp3->id3);
        if (ret < 0)
            return ret;
    }

    if (!mp3->pics_to_write) {
        if (mp3->id3v2_version)
            ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
        mp3_write_xing(s);
    }

    return 0;
}

AVOutputFormat ff_mp3_muxer = {
    .name              = "mp3",
    .long_name         = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
    .mime_type         = "audio/mpeg",
    .extensions        = "mp3",
    .priv_data_size    = sizeof(MP3Context),
    .audio_codec       = AV_CODEC_ID_MP3,
    .video_codec       = AV_CODEC_ID_PNG,
    .write_header      = mp3_write_header,
    .write_packet      = mp3_write_packet,
    .write_trailer     = mp3_write_trailer,
    .query_codec       = query_codec,
    .flags             = AVFMT_NOTIMESTAMPS,
    .priv_class        = &mp3_muxer_class,
};
#endif
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* MP3 muxer
	3	* Copyright (c) 2003 Fabrice Bellard
	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 "avformat.h"
	23	#include "avio_internal.h"
	24	#include "id3v1.h"
	25	#include "id3v2.h"
	26	#include "rawenc.h"
	27	#include "libavutil/avstring.h"
	28	#include "libavcodec/mpegaudio.h"
	29	#include "libavcodec/mpegaudiodata.h"
	30	#include "libavcodec/mpegaudiodecheader.h"
	31	#include "libavutil/intreadwrite.h"
	32	#include "libavutil/opt.h"
	33	#include "libavutil/dict.h"
	34	#include "libavutil/avassert.h"
	35
	36	static int id3v1_set_string(AVFormatContext s, const char key,
	37	uint8_t *buf, int buf_size)
	38	{
	39	AVDictionaryEntry *tag;
	40	if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
	41	av_strlcpy(buf, tag->value, buf_size);
	42	return !!tag;
	43	}
	44
	45	static int id3v1_create_tag(AVFormatContext s, uint8_t buf)
	46	{
	47	AVDictionaryEntry *tag;
	48	int i, count = 0;
	49
	50	memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
	51	buf[0] = 'T';
	52	buf[1] = 'A';
	53	buf[2] = 'G';
	54	/* we knowingly overspecify each tag length by one byte to compensate for the mandatory null byte added by av_strlcpy */
	55	count += id3v1_set_string(s, "TIT2", buf + 3, 30 + 1); //title
	56	count += id3v1_set_string(s, "TPE1", buf + 33, 30 + 1); //author\|artist
	57	count += id3v1_set_string(s, "TALB", buf + 63, 30 + 1); //album
	58	count += id3v1_set_string(s, "TDRL", buf + 93, 4 + 1); //date
	59	count += id3v1_set_string(s, "comment", buf + 97, 30 + 1);
	60	if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
	61	buf[125] = 0;
	62	buf[126] = atoi(tag->value);
	63	count++;
	64	}
65	buf[127] = 0xFF; /* default to unknown genre */
66	if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
67	for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
68	if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
69	buf[127] = i;
70	count++;
71	break;
72	}
73	}
74	}
75	return count;
76	}
77
78	#define XING_NUM_BAGS 400
79	#define XING_TOC_SIZE 100
80	// maximum size of the xing frame: offset/Xing/flags/frames/size/TOC
81	#define XING_MAX_SIZE (32 + 4 + 4 + 4 + 4 + XING_TOC_SIZE)
82
83	typedef struct MP3Context {
84	const AVClass *class;
85	ID3v2EncContext id3;
86	int id3v2_version;
87	int write_id3v1;
88	int write_xing;
89
90	/* xing header */
91	int64_t xing_offset;
92	int32_t frames;
93	int32_t size;
94	uint32_t want;
95	uint32_t seen;
96	uint32_t pos;
97	uint64_t bag[XING_NUM_BAGS];
98	int initial_bitrate;
99	int has_variable_bitrate;
100
101	/* index of the audio stream */
102	int audio_stream_idx;
103	/* number of attached pictures we still need to write */
104	int pics_to_write;
105
106	/* audio packets are queued here until we get all the attached pictures */
107	AVPacketList queue, queue_end;
108	} MP3Context;
109
110	static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};
111
112	/*
113	* Write an empty XING header and initialize respective data.
114	*/
115	static int mp3_write_xing(AVFormatContext *s)
116	{
117	MP3Context *mp3 = s->priv_data;
118	AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec;
119	int32_t header;
120	MPADecodeHeader mpah;
121	int srate_idx, i, channels;
122	int bitrate_idx;
123	int best_bitrate_idx = -1;
124	int best_bitrate_error = INT_MAX;
125	int xing_offset;
126	int ver = 0;
127	int bytes_needed;
128	const char *vendor = (s->flags & AVFMT_FLAG_BITEXACT) ? "Lavf" : LIBAVFORMAT_IDENT;
129
130	if (!s->pb->seekable \|\| !mp3->write_xing)
131	return 0;
132
133	for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
134	const uint16_t base_freq = avpriv_mpa_freq_tab[i];
135
136	if (codec->sample_rate == base_freq) ver = 0x3; // MPEG 1
137	else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
138	else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
139	else continue;
140
141	srate_idx = i;
142	break;
143	}
144	if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
145	av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing header.\n");
146	return -1;
147	}
148
149	switch (codec->channels) {
150	case 1: channels = MPA_MONO; break;
151	case 2: channels = MPA_STEREO; break;
152	default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
153	"not writing Xing header.\n");
154	return -1;
155	}
156
157	/* dummy MPEG audio header */
158	header = 0xffU << 24; // sync
159	header \|= (0x7 << 5 \| ver << 3 \| 0x1 << 1 \| 0x1) << 16; // sync/audio-version/layer 3/no crc*/
160	header \|= (srate_idx << 2) << 8;
161	header \|= channels << 6;
162
163	for (bitrate_idx = 1; bitrate_idx < 15; bitrate_idx++) {
164	int bit_rate = 1000 * avpriv_mpa_bitrate_tab[ver != 3][3 - 1][bitrate_idx];
165	int error = FFABS(bit_rate - codec->bit_rate);
166
167	if (error < best_bitrate_error) {
168	best_bitrate_error = error;
169	best_bitrate_idx = bitrate_idx;
170	}
171	}
172	av_assert0(best_bitrate_idx >= 0);
173
174	for (bitrate_idx = best_bitrate_idx; ; bitrate_idx++) {
175	int32_t mask = bitrate_idx << (4 + 8);
176	if (15 == bitrate_idx)
177	return -1;
178	header \|= mask;
179
180	avpriv_mpegaudio_decode_header(&mpah, header);
181	xing_offset=xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1];
182	bytes_needed = 4 // header
183	+ xing_offset
184	+ 4 // xing tag
185	+ 4 // frames/size/toc flags
186	+ 4 // frames
187	+ 4 // size
188	+ XING_TOC_SIZE // toc
189	+ 24
190	;
191
192	if (bytes_needed <= mpah.frame_size)
193	break;
194
195	header &= ~mask;
196	}
197
198	avio_wb32(s->pb, header);
199
200	ffio_fill(s->pb, 0, xing_offset);
201	mp3->xing_offset = avio_tell(s->pb);
202	ffio_wfourcc(s->pb, "Xing");
203	avio_wb32(s->pb, 0x01 \| 0x02 \| 0x04); // frames / size / TOC
204
205	mp3->size = mpah.frame_size;
206	mp3->want=1;
207	mp3->seen=0;
208	mp3->pos=0;
209
210	avio_wb32(s->pb, 0); // frames
211	avio_wb32(s->pb, 0); // size
212
213	// toc
214	for (i = 0; i < XING_TOC_SIZE; ++i)
215	avio_w8(s->pb, (uint8_t)(255 * i / XING_TOC_SIZE));
216
217	for (i = 0; i < strlen(vendor); ++i)
218	avio_w8(s->pb, vendor[i]);
219	for (; i < 21; ++i)
220	avio_w8(s->pb, 0);
221	avio_wb24(s->pb, FFMAX(codec->delay - 528 - 1, 0)<<12);
222
223	ffio_fill(s->pb, 0, mpah.frame_size - bytes_needed);
224
225	return 0;
226	}
227
228	/*
229	* Add a frame to XING data.
230	* Following lame's "VbrTag.c".
231	*/
232	static void mp3_xing_add_frame(MP3Context mp3, AVPacket pkt)
233	{
234	int i;
235
236	mp3->frames++;
237	mp3->seen++;
238	mp3->size += pkt->size;
239
240	if (mp3->want == mp3->seen) {
241	mp3->bag[mp3->pos] = mp3->size;
242
243	if (XING_NUM_BAGS == ++mp3->pos) {
244	/* shrink table to half size by throwing away each second bag. */
245	for (i = 1; i < XING_NUM_BAGS; i += 2)
246	mp3->bag[i >> 1] = mp3->bag[i];
247
248	/* double wanted amount per bag. */
249	mp3->want *= 2;
250	/* adjust current position to half of table size. */
251	mp3->pos = XING_NUM_BAGS / 2;
252	}
253
254	mp3->seen = 0;
255	}
256	}
257
258	static int mp3_write_audio_packet(AVFormatContext s, AVPacket pkt)
259	{
260	MP3Context *mp3 = s->priv_data;
261
262	if (pkt->data && pkt->size >= 4) {
263	MPADecodeHeader mpah;
264	int av_unused base;
265	uint32_t h;
266
267	h = AV_RB32(pkt->data);
268	if (ff_mpa_check_header(h) == 0) {
269	avpriv_mpegaudio_decode_header(&mpah, h);
270	if (!mp3->initial_bitrate)
271	mp3->initial_bitrate = mpah.bit_rate;
272	if ((mpah.bit_rate == 0) \|\| (mp3->initial_bitrate != mpah.bit_rate))
273	mp3->has_variable_bitrate = 1;
274	} else {
275	av_log(s, AV_LOG_WARNING, "Audio packet of size %d (starting with %08X...) "
276	"is invalid, writing it anyway.\n", pkt->size, h);
277	}
278
279	#ifdef FILTER_VBR_HEADERS
280	/* filter out XING and INFO headers. */
281	base = 4 + xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1];
282
283	if (base + 4 <= pkt->size) {
284	uint32_t v = AV_RB32(pkt->data + base);
285
286	if (MKBETAG('X','i','n','g') == v \|\| MKBETAG('I','n','f','o') == v)
287	return 0;
288	}
289
290	/* filter out VBRI headers. */
291	base = 4 + 32;
292
293	if (base + 4 <= pkt->size && MKBETAG('V','B','R','I') == AV_RB32(pkt->data + base))
294	return 0;
295	#endif
296
297	if (mp3->xing_offset)
298	mp3_xing_add_frame(mp3, pkt);
299	}
300
301	return ff_raw_write_packet(s, pkt);
302	}
303
304	static int mp3_queue_flush(AVFormatContext *s)
305	{
306	MP3Context *mp3 = s->priv_data;
307	AVPacketList *pktl;
308	int ret = 0, write = 1;
309
310	ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
311	mp3_write_xing(s);
312
313	while ((pktl = mp3->queue)) {
314	if (write && (ret = mp3_write_audio_packet(s, &pktl->pkt)) < 0)
315	write = 0;
316	av_free_packet(&pktl->pkt);
317	mp3->queue = pktl->next;
318	av_freep(&pktl);
319	}
320	mp3->queue_end = NULL;
321	return ret;
322	}
323
324	static void mp3_update_xing(AVFormatContext *s)
325	{
326	MP3Context *mp3 = s->priv_data;
327	int i;
328
329	/* replace "Xing" identification string with "Info" for CBR files. */
330	if (!mp3->has_variable_bitrate) {
331	avio_seek(s->pb, mp3->xing_offset, SEEK_SET);
332	ffio_wfourcc(s->pb, "Info");
333	}
334
335	avio_seek(s->pb, mp3->xing_offset + 8, SEEK_SET);
336	avio_wb32(s->pb, mp3->frames);
337	avio_wb32(s->pb, mp3->size);
338
339	avio_w8(s->pb, 0); // first toc entry has to be zero.
340
341	for (i = 1; i < XING_TOC_SIZE; ++i) {
342	int j = i * mp3->pos / XING_TOC_SIZE;
343	int seek_point = 256LL * mp3->bag[j] / mp3->size;
344	avio_w8(s->pb, FFMIN(seek_point, 255));
345	}
346
347	avio_seek(s->pb, 0, SEEK_END);
348	}
349
350	static int mp3_write_trailer(struct AVFormatContext *s)
351	{
352	uint8_t buf[ID3v1_TAG_SIZE];
353	MP3Context *mp3 = s->priv_data;
354
355	if (mp3->pics_to_write) {
356	av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
357	"attached pictures.\n");
358	mp3_queue_flush(s);
359	}
360
361	/* write the id3v1 tag */
362	if (mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
363	avio_write(s->pb, buf, ID3v1_TAG_SIZE);
364	}
365
366	if (mp3->xing_offset)
367	mp3_update_xing(s);
368
369	return 0;
370	}
371
372	static int query_codec(enum AVCodecID id, int std_compliance)
373	{
374	const CodecMime *cm= ff_id3v2_mime_tags;
375	while(cm->id != AV_CODEC_ID_NONE) {
376	if(id == cm->id)
377	return MKTAG('A', 'P', 'I', 'C');
378	cm++;
379	}
380	return -1;
381	}
382
383	#if CONFIG_MP2_MUXER
384	AVOutputFormat ff_mp2_muxer = {
385	.name = "mp2",
386	.long_name = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
387	.mime_type = "audio/mpeg",
388	.extensions = "mp2,m2a,mpa",
389	.audio_codec = AV_CODEC_ID_MP2,
390	.video_codec = AV_CODEC_ID_NONE,
391	.write_packet = ff_raw_write_packet,
392	.flags = AVFMT_NOTIMESTAMPS,
393	};
394	#endif
395
396	#if CONFIG_MP3_MUXER
397
398	static const AVOption options[] = {
399	{ "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
400	offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 0, 4, AV_OPT_FLAG_ENCODING_PARAM},
401	{ "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
402	offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
403	{ "write_xing", "Write the Xing header containing file duration.",
404	offsetof(MP3Context, write_xing), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
405	{ NULL },
406	};
407
408	static const AVClass mp3_muxer_class = {
409	.class_name = "MP3 muxer",
410	.item_name = av_default_item_name,
411	.option = options,
412	.version = LIBAVUTIL_VERSION_INT,
413	};
414
415	static int mp3_write_packet(AVFormatContext s, AVPacket pkt)
416	{
417	MP3Context *mp3 = s->priv_data;
418
419	if (pkt->stream_index == mp3->audio_stream_idx) {
420	if (mp3->pics_to_write) {
421	/* buffer audio packets until we get all the pictures */
422	AVPacketList pktl = av_mallocz(sizeof(pktl));
423	int ret;
424	if (!pktl) {
425	av_log(s, AV_LOG_WARNING, "Not enough memory to buffer audio. Skipping picture streams\n");
426	mp3->pics_to_write = 0;
427	mp3_queue_flush(s);
428	return mp3_write_audio_packet(s, pkt);
429	}
430
431	ret = av_copy_packet(&pktl->pkt, pkt);
432	if (ret < 0) {
433	av_freep(&pktl);
434	return ret;
435	}
436
437	if (mp3->queue_end)
438	mp3->queue_end->next = pktl;
439	else
440	mp3->queue = pktl;
441	mp3->queue_end = pktl;
442	} else
443	return mp3_write_audio_packet(s, pkt);
444	} else {
445	int ret;
446
447	/* warn only once for each stream */
448	if (s->streams[pkt->stream_index]->nb_frames == 1) {
449	av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
450	" ignoring.\n", pkt->stream_index);
451	}
452	if (!mp3->pics_to_write \|\| s->streams[pkt->stream_index]->nb_frames >= 1)
453	return 0;
454
455	if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
456	return ret;
457	mp3->pics_to_write--;
458
459	/* flush the buffered audio packets */
460	if (!mp3->pics_to_write &&
461	(ret = mp3_queue_flush(s)) < 0)
462	return ret;
463	}
464
465	return 0;
466	}
467
468	/**
469	* Write an ID3v2 header at beginning of stream
470	*/
471
472	static int mp3_write_header(struct AVFormatContext *s)
473	{
474	MP3Context *mp3 = s->priv_data;
475	int ret, i;
476
477	if (mp3->id3v2_version &&
478	mp3->id3v2_version != 3 &&
479	mp3->id3v2_version != 4) {
480	av_log(s, AV_LOG_ERROR, "Invalid ID3v2 version requested: %d. Only "
481	"3, 4 or 0 (disabled) are allowed.\n", mp3->id3v2_version);
482	return AVERROR(EINVAL);
483	}
484
485	/* check the streams -- we want exactly one audio and arbitrary number of
486	* video (attached pictures) */
487	mp3->audio_stream_idx = -1;
488	for (i = 0; i < s->nb_streams; i++) {
489	AVStream *st = s->streams[i];
490	if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
491	if (mp3->audio_stream_idx >= 0 \|\| st->codec->codec_id != AV_CODEC_ID_MP3) {
492	av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
493	"audio stream is required.\n");
494	return AVERROR(EINVAL);
495	}
496	mp3->audio_stream_idx = i;
497	} else if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) {
498	av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
499	return AVERROR(EINVAL);
500	}
501	}
502	if (mp3->audio_stream_idx < 0) {
503	av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
504	return AVERROR(EINVAL);
505	}
506	mp3->pics_to_write = s->nb_streams - 1;
507
508	if (mp3->pics_to_write && !mp3->id3v2_version) {
509	av_log(s, AV_LOG_ERROR, "Attached pictures were requested, but the "
510	"ID3v2 header is disabled.\n");
511	return AVERROR(EINVAL);
512	}
513
514	if (mp3->id3v2_version) {
515	ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
516	ret = ff_id3v2_write_metadata(s, &mp3->id3);
517	if (ret < 0)
518	return ret;
519	}
520
521	if (!mp3->pics_to_write) {
522	if (mp3->id3v2_version)
523	ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
524	mp3_write_xing(s);
525	}
526
527	return 0;
528	}
529
530	AVOutputFormat ff_mp3_muxer = {
531	.name = "mp3",
532	.long_name = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
533	.mime_type = "audio/mpeg",
534	.extensions = "mp3",
535	.priv_data_size = sizeof(MP3Context),
536	.audio_codec = AV_CODEC_ID_MP3,
537	.video_codec = AV_CODEC_ID_PNG,
538	.write_header = mp3_write_header,
539	.write_packet = mp3_write_packet,
540	.write_trailer = mp3_write_trailer,
541	.query_codec = query_codec,
542	.flags = AVFMT_NOTIMESTAMPS,
543	.priv_class = &mp3_muxer_class,
544	};
545	#endif