| /* |
| * 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 "libavcodec/mpegaudio.h" |
| #include "libavcodec/mpegaudiodata.h" |
| #include "libavcodec/mpegaudiodecheader.h" |
| #include "libavformat/avio_internal.h" |
| #include "libavutil/dict.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 VBR_NUM_BAGS 400 |
| #define VBR_TOC_SIZE 100 |
| |
| typedef struct MP3Context { |
| const AVClass *class; |
| int id3v2_version; |
| int write_id3v1; |
| int64_t frames_offset; |
| int32_t frames; |
| int32_t size; |
| uint32_t want; |
| uint32_t seen; |
| uint32_t pos; |
| uint64_t bag[VBR_NUM_BAGS]; |
| } MP3Context; |
| |
| static int mp2_write_trailer(struct AVFormatContext *s) |
| { |
| uint8_t buf[ID3v1_TAG_SIZE]; |
| MP3Context *mp3 = s->priv_data; |
| |
| /* write the id3v1 tag */ |
| if (mp3 && mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) { |
| avio_write(s->pb, buf, ID3v1_TAG_SIZE); |
| } |
| |
| /* write number of frames */ |
| if (mp3 && mp3->frames_offset) { |
| avio_seek(s->pb, mp3->frames_offset, SEEK_SET); |
| avio_wb32(s->pb, s->streams[0]->nb_frames); |
| avio_seek(s->pb, 0, SEEK_END); |
| } |
| |
| avio_flush(s->pb); |
| |
| return 0; |
| } |
| |
| #if CONFIG_MP2_MUXER |
| AVOutputFormat ff_mp2_muxer = { |
| .name = "mp2", |
| .long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 2"), |
| .mime_type = "audio/x-mpeg", |
| .extensions = "mp2,m2a", |
| .audio_codec = CODEC_ID_MP2, |
| .video_codec = CODEC_ID_NONE, |
| .write_packet = ff_raw_write_packet, |
| .write_trailer = mp2_write_trailer, |
| .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, {.dbl = 4}, 3, 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, {.dbl = 0}, 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 const int64_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) |
| { |
| AVCodecContext *codec = s->streams[0]->codec; |
| MP3Context *mp3 = s->priv_data; |
| int bitrate_idx; |
| int best_bitrate_idx; |
| int best_bitrate_error= INT_MAX; |
| int64_t xing_offset; |
| int32_t header, mask; |
| MPADecodeHeader c; |
| int srate_idx, i, channels; |
| int needed; |
| |
| for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) |
| if (avpriv_mpa_freq_tab[i] == codec->sample_rate) { |
| srate_idx = i; |
| break; |
| } |
| if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) { |
| av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n"); |
| return -1; |
| } |
| |
| switch (codec->channels) { |
| case 1: channels = MPA_MONO; break; |
| case 2: channels = MPA_STEREO; break; |
| default: av_log(s, AV_LOG_ERROR, "Unsupported number of channels.\n"); return -1; |
| } |
| |
| /* dummy MPEG audio header */ |
| header = 0xff << 24; // sync |
| header |= (0x7 << 5 | 0x3 << 3 | 0x1 << 1 | 0x1) << 16; // sync/mpeg-1/layer 3/no crc*/ |
| header |= (srate_idx << 2) << 8; |
| header |= channels << 6; |
| |
| for (bitrate_idx=1; bitrate_idx<15; bitrate_idx++) { |
| int error; |
| avpriv_mpegaudio_decode_header(&c, header | (bitrate_idx << (4+8))); |
| error= FFABS(c.bit_rate - codec->bit_rate); |
| if(error < best_bitrate_error){ |
| best_bitrate_error= error; |
| best_bitrate_idx = bitrate_idx; |
| } |
| } |
| |
| for (bitrate_idx= best_bitrate_idx;; bitrate_idx++) { |
| if (15 == bitrate_idx) |
| return -1; |
| mask = bitrate_idx << (4+8); |
| header |= mask; |
| avpriv_mpegaudio_decode_header(&c, header); |
| xing_offset=xing_offtbl[c.lsf == 1][c.nb_channels == 1]; |
| needed = 4 // header |
| + xing_offset |
| + 4 // xing tag |
| + 4 // frames/size/toc flags |
| + 4 // frames |
| + 4 // size |
| + VBR_TOC_SIZE; // toc |
| |
| if (needed <= c.frame_size) |
| break; |
| header &= ~mask; |
| } |
| |
| avio_wb32(s->pb, header); |
| ffio_fill(s->pb, 0, xing_offset); |
| avio_wb32(s->pb, MKBETAG('X', 'i', 'n', 'g')); |
| avio_wb32(s->pb, 0x01 | 0x02 | 0x04); // frames/size/toc |
| |
| mp3->frames_offset = avio_tell(s->pb); |
| mp3->size = c.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 < VBR_TOC_SIZE; ++i) |
| avio_w8(s->pb, (uint8_t)(255 * i / VBR_TOC_SIZE)); |
| |
| ffio_fill(s->pb, 0, c.frame_size - needed); |
| avio_flush(s->pb); |
| |
| return 0; |
| } |
| |
| /* |
| * Add a frame to XING data. |
| * Following lame's "VbrTag.c". |
| */ |
| static void mp3_xing_add_frame(AVFormatContext *s, AVPacket *pkt) |
| { |
| MP3Context *mp3 = s->priv_data; |
| int i; |
| |
| ++mp3->frames; |
| mp3->size += pkt->size; |
| |
| if (mp3->want == ++mp3->seen) { |
| mp3->bag[mp3->pos] = mp3->size; |
| |
| if (VBR_NUM_BAGS == ++mp3->pos) { |
| /* shrink table to half size by throwing away each second bag. */ |
| for (i = 1; i < VBR_NUM_BAGS; i += 2) |
| mp3->bag[i >> 1] = mp3->bag[i]; |
| |
| /* double wanted amount per bag. */ |
| mp3->want <<= 1; |
| /* adjust current position to half of table size. */ |
| mp3->pos >>= 1; |
| } |
| |
| mp3->seen = 0; |
| } |
| } |
| |
| static void mp3_fix_xing(AVFormatContext *s) |
| { |
| MP3Context *mp3 = s->priv_data; |
| int i; |
| |
| avio_flush(s->pb); |
| avio_seek(s->pb, mp3->frames_offset, 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 < VBR_TOC_SIZE; ++i) { |
| int j = i * mp3->pos / VBR_TOC_SIZE; |
| int seek_point = 256LL * mp3->bag[j] / mp3->size; |
| avio_w8(s->pb, FFMIN(seek_point, 255)); |
| } |
| |
| avio_flush(s->pb); |
| avio_seek(s->pb, 0, SEEK_END); |
| } |
| |
| /** |
| * Write an ID3v2 header at beginning of stream |
| */ |
| |
| static int mp3_write_header(struct AVFormatContext *s) |
| { |
| MP3Context *mp3 = s->priv_data; |
| int ret; |
| |
| ret = ff_id3v2_write(s, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC); |
| if (ret < 0) |
| return ret; |
| |
| if (s->pb->seekable) |
| mp3_write_xing(s); |
| |
| return 0; |
| } |
| |
| static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| if (! pkt || ! pkt->data || pkt->size < 4) |
| return ff_raw_write_packet(s, pkt); |
| else { |
| MP3Context *mp3 = s->priv_data; |
| #ifdef FILTER_VBR_HEADERS |
| MPADecodeHeader c; |
| int base; |
| |
| ff_mpegaudio_decode_header(&c, AV_RB32(pkt->data)); |
| |
| /* filter out XING and INFO headers. */ |
| base = 4 + xing_offtbl[c.lsf == 1][c.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->frames_offset) |
| mp3_xing_add_frame(s, pkt); |
| |
| return ff_raw_write_packet(s, pkt); |
| } |
| } |
| |
| static int mp3_write_trailer(AVFormatContext *s) |
| { |
| MP3Context *mp3 = s->priv_data; |
| int ret=mp2_write_trailer(s); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (mp3->frames_offset) |
| mp3_fix_xing(s); |
| |
| return 0; |
| } |
| |
| AVOutputFormat ff_mp3_muxer = { |
| .name = "mp3", |
| .long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 3"), |
| .mime_type = "audio/x-mpeg", |
| .extensions = "mp3", |
| .priv_data_size = sizeof(MP3Context), |
| .audio_codec = CODEC_ID_MP3, |
| .video_codec = CODEC_ID_NONE, |
| .write_header = mp3_write_header, |
| .write_packet = mp3_write_packet, |
| .write_trailer = mp3_write_trailer, |
| .flags = AVFMT_NOTIMESTAMPS, |
| .priv_class = &mp3_muxer_class, |
| }; |
| #endif |
