diff options
Diffstat (limited to 'libavformat/mp3enc.c')
| -rw-r--r-- | libavformat/mp3enc.c | 236 |
1 files changed, 201 insertions, 35 deletions
diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c index fb46ac94ca..b2c1b4211e 100644 --- a/libavformat/mp3enc.c +++ b/libavformat/mp3enc.c @@ -2,20 +2,20 @@ * MP3 muxer * Copyright (c) 2003 Fabrice Bellard * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -30,6 +30,10 @@ #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" #include "libavutil/avassert.h" @@ -51,11 +55,12 @@ static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf) buf[0] = 'T'; buf[1] = 'A'; buf[2] = 'G'; - count += id3v1_set_string(s, "TIT2", buf + 3, 30); //title - count += id3v1_set_string(s, "TPE1", buf + 33, 30); //author|artist - count += id3v1_set_string(s, "TALB", buf + 63, 30); //album - count += id3v1_set_string(s, "TDRL", buf + 93, 4); //date - count += id3v1_set_string(s, "comment", buf + 97, 30); + /* 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); @@ -74,12 +79,21 @@ static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf) return count; } +#define VBR_NUM_BAGS 400 +#define VBR_TOC_SIZE 100 + typedef struct MP3Context { const AVClass *class; ID3v2EncContext id3; int id3v2_version; int write_id3v1; - int64_t nb_frames_offset; + 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]; /* index of the audio stream */ int audio_stream_idx; @@ -90,19 +104,26 @@ typedef struct MP3Context { AVPacketList *queue, *queue_end; } MP3Context; -/* insert a dummy frame containing number of frames */ -static void mp3_write_xing(AVFormatContext *s) +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) { MP3Context *mp3 = s->priv_data; AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec; - int bitrate_idx = 1; // 32 kbps - int64_t xing_offset = (codec->channels == 2) ? 32 : 17; - int32_t header; - MPADecodeHeader mpah; - int srate_idx, i, channels; + int bitrate_idx; + int best_bitrate_idx = -1; + int best_bitrate_error= INT_MAX; + int64_t xing_offset; + int32_t header, mask; + MPADecodeHeader c; + int srate_idx, i, channels; + int needed; if (!s->pb->seekable) - return; + return 0; for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) if (avpriv_mpa_freq_tab[i] == codec->sample_rate) { @@ -111,32 +132,162 @@ static void mp3_write_xing(AVFormatContext *s) } if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) { av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n"); - return; + 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; + 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 |= (bitrate_idx << 4 | srate_idx << 2) << 8; + header |= (srate_idx << 2) << 8; header |= channels << 6; - avio_wb32(s->pb, header); - avpriv_mpegaudio_decode_header(&mpah, header); + 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; + } + } + av_assert0(best_bitrate_idx >= 0); + + 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); - ffio_wfourcc(s->pb, "Xing"); - avio_wb32(s->pb, 0x1); // only number of frames - mp3->nb_frames_offset = avio_tell(s->pb); - avio_wb32(s->pb, 0); + 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. - mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4; - ffio_fill(s->pb, 0, mpah.frame_size); + 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); +} + +static int mp3_write_packet_internal(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_queue_flush(AVFormatContext *s) @@ -149,7 +300,7 @@ static int mp3_queue_flush(AVFormatContext *s) mp3_write_xing(s); while ((pktl = mp3->queue)) { - if (write && (ret = ff_raw_write_packet(s, &pktl->pkt)) < 0) + if (write && (ret = mp3_write_packet_internal(s, &pktl->pkt)) < 0) write = 0; av_free_packet(&pktl->pkt); mp3->queue = pktl->next; @@ -159,7 +310,7 @@ static int mp3_queue_flush(AVFormatContext *s) return ret; } -static int mp3_write_trailer(struct AVFormatContext *s) +static int mp2_write_trailer(struct AVFormatContext *s) { uint8_t buf[ID3v1_TAG_SIZE]; MP3Context *mp3 = s->priv_data; @@ -176,8 +327,8 @@ static int mp3_write_trailer(struct AVFormatContext *s) } /* write number of frames */ - if (mp3 && mp3->nb_frames_offset) { - avio_seek(s->pb, mp3->nb_frames_offset, SEEK_SET); + if (mp3 && mp3->frames_offset) { + avio_seek(s->pb, mp3->frames_offset, SEEK_SET); avio_wb32(s->pb, s->streams[mp3->audio_stream_idx]->nb_frames); avio_seek(s->pb, 0, SEEK_END); } @@ -196,7 +347,8 @@ AVOutputFormat ff_mp2_muxer = { .audio_codec = CODEC_ID_MP2, .video_codec = CODEC_ID_NONE, .write_packet = ff_raw_write_packet, - .write_trailer = mp3_write_trailer, + .write_trailer = mp2_write_trailer, + .flags = AVFMT_NOTIMESTAMPS, }; #endif @@ -237,7 +389,7 @@ static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt) mp3->queue = pktl; mp3->queue_end = pktl; } else - return ff_raw_write_packet(s, pkt); + return mp3_write_packet_internal(s, pkt); } else { int ret; @@ -307,6 +459,20 @@ static int mp3_write_header(struct AVFormatContext *s) return 0; } +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"), |