f2f2e7627f
As indicated in the function documentation, the header MUST be checked prior to calling it because no consistency check is done there. CC:libav-stable@libav.org
498 lines
15 KiB
C
498 lines
15 KiB
C
/*
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* MP3 muxer
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* Copyright (c) 2003 Fabrice Bellard
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avformat.h"
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#include "avio_internal.h"
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#include "id3v1.h"
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#include "id3v2.h"
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#include "rawenc.h"
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#include "libavutil/avstring.h"
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#include "libavcodec/mpegaudio.h"
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#include "libavcodec/mpegaudiodata.h"
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#include "libavcodec/mpegaudiodecheader.h"
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#include "libavutil/intreadwrite.h"
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#include "libavutil/opt.h"
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#include "libavutil/dict.h"
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#include "libavutil/avassert.h"
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static int id3v1_set_string(AVFormatContext *s, const char *key,
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uint8_t *buf, int buf_size)
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{
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AVDictionaryEntry *tag;
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if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
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av_strlcpy(buf, tag->value, buf_size);
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return !!tag;
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}
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static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
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{
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AVDictionaryEntry *tag;
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int i, count = 0;
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memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
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buf[0] = 'T';
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buf[1] = 'A';
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buf[2] = 'G';
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count += id3v1_set_string(s, "TIT2", buf + 3, 30); //title
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count += id3v1_set_string(s, "TPE1", buf + 33, 30); //author|artist
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count += id3v1_set_string(s, "TALB", buf + 63, 30); //album
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count += id3v1_set_string(s, "TDRL", buf + 93, 4); //date
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count += id3v1_set_string(s, "comment", buf + 97, 30);
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if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
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buf[125] = 0;
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buf[126] = atoi(tag->value);
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count++;
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}
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buf[127] = 0xFF; /* default to unknown genre */
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if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
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for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
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if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
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buf[127] = i;
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count++;
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break;
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}
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}
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}
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return count;
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}
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#define XING_NUM_BAGS 400
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#define XING_TOC_SIZE 100
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// maximum size of the xing frame: offset/Xing/flags/frames/size/TOC
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#define XING_MAX_SIZE (32 + 4 + 4 + 4 + 4 + XING_TOC_SIZE)
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typedef struct MP3Context {
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const AVClass *class;
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ID3v2EncContext id3;
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int id3v2_version;
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int write_id3v1;
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int write_xing;
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/* xing header */
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int64_t xing_offset;
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int32_t frames;
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int32_t size;
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uint32_t want;
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uint32_t seen;
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uint32_t pos;
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uint64_t bag[XING_NUM_BAGS];
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int initial_bitrate;
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int has_variable_bitrate;
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/* index of the audio stream */
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int audio_stream_idx;
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/* number of attached pictures we still need to write */
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int pics_to_write;
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/* audio packets are queued here until we get all the attached pictures */
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AVPacketList *queue, *queue_end;
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} MP3Context;
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static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};
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/*
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* Write an empty XING header and initialize respective data.
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*/
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static void mp3_write_xing(AVFormatContext *s)
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{
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MP3Context *mp3 = s->priv_data;
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AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec;
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int32_t header;
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MPADecodeHeader mpah;
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int srate_idx, i, channels;
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int bitrate_idx;
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int best_bitrate_idx;
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int best_bitrate_error = INT_MAX;
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int xing_offset;
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int ver = 0;
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int lsf, bytes_needed;
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if (!s->pb->seekable || !mp3->write_xing)
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return;
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for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
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const uint16_t base_freq = avpriv_mpa_freq_tab[i];
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if (codec->sample_rate == base_freq) ver = 0x3; // MPEG 1
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else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
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else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
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else continue;
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srate_idx = i;
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break;
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}
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if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
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av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing "
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"header.\n");
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return;
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}
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switch (codec->channels) {
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case 1: channels = MPA_MONO; break;
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case 2: channels = MPA_STEREO; break;
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default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
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"not writing Xing header.\n");
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return;
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}
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/* dummy MPEG audio header */
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header = 0xff << 24; // sync
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header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
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header |= (srate_idx << 2) << 8;
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header |= channels << 6;
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lsf = !((header & (1 << 20) && header & (1 << 19)));
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xing_offset = xing_offtbl[ver != 3][channels == 1];
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bytes_needed = 4 // header
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+ xing_offset
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+ 4 // xing tag
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+ 4 // frames/size/toc flags
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+ 4 // frames
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+ 4 // size
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+ XING_TOC_SIZE; // toc
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for (bitrate_idx = 1; bitrate_idx < 15; bitrate_idx++) {
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int bit_rate = 1000 * avpriv_mpa_bitrate_tab[lsf][3 - 1][bitrate_idx];
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int error = FFABS(bit_rate - codec->bit_rate);
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if (error < best_bitrate_error){
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best_bitrate_error = error;
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best_bitrate_idx = bitrate_idx;
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}
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}
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for (bitrate_idx = best_bitrate_idx; bitrate_idx < 15; bitrate_idx++) {
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int32_t mask = bitrate_idx << (4 + 8);
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header |= mask;
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avpriv_mpegaudio_decode_header(&mpah, header);
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if (bytes_needed <= mpah.frame_size)
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break;
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header &= ~mask;
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}
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avio_wb32(s->pb, header);
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avpriv_mpegaudio_decode_header(&mpah, header);
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av_assert0(mpah.frame_size >= XING_MAX_SIZE);
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ffio_fill(s->pb, 0, xing_offset);
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mp3->xing_offset = avio_tell(s->pb);
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ffio_wfourcc(s->pb, "Xing");
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avio_wb32(s->pb, 0x01 | 0x02 | 0x04); // frames / size / TOC
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mp3->size = mpah.frame_size;
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mp3->want = 1;
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avio_wb32(s->pb, 0); // frames
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avio_wb32(s->pb, 0); // size
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// TOC
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for (i = 0; i < XING_TOC_SIZE; i++)
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avio_w8(s->pb, 255 * i / XING_TOC_SIZE);
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ffio_fill(s->pb, 0, mpah.frame_size - bytes_needed);
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}
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/*
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* Add a frame to XING data.
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* Following lame's "VbrTag.c".
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*/
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static void mp3_xing_add_frame(MP3Context *mp3, AVPacket *pkt)
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{
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int i;
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mp3->frames++;
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mp3->seen++;
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mp3->size += pkt->size;
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if (mp3->want == mp3->seen) {
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mp3->bag[mp3->pos] = mp3->size;
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if (XING_NUM_BAGS == ++mp3->pos) {
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/* shrink table to half size by throwing away each second bag. */
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for (i = 1; i < XING_NUM_BAGS; i += 2)
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mp3->bag[i / 2] = mp3->bag[i];
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/* double wanted amount per bag. */
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mp3->want *= 2;
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/* adjust current position to half of table size. */
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mp3->pos = XING_NUM_BAGS / 2;
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}
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mp3->seen = 0;
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}
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}
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static int mp3_write_audio_packet(AVFormatContext *s, AVPacket *pkt)
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{
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MP3Context *mp3 = s->priv_data;
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if (mp3->xing_offset && pkt->size >= 4) {
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MPADecodeHeader c;
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uint32_t h;
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h = AV_RB32(pkt->data);
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if (ff_mpa_check_header(h) == 0) {
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avpriv_mpegaudio_decode_header(&c, h);
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if (!mp3->initial_bitrate)
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mp3->initial_bitrate = c.bit_rate;
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if ((c.bit_rate == 0) || (mp3->initial_bitrate != c.bit_rate))
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mp3->has_variable_bitrate = 1;
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}
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mp3_xing_add_frame(mp3, pkt);
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}
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return ff_raw_write_packet(s, pkt);
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}
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static int mp3_queue_flush(AVFormatContext *s)
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{
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MP3Context *mp3 = s->priv_data;
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AVPacketList *pktl;
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int ret = 0, write = 1;
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ff_id3v2_finish(&mp3->id3, s->pb);
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mp3_write_xing(s);
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while ((pktl = mp3->queue)) {
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if (write && (ret = mp3_write_audio_packet(s, &pktl->pkt)) < 0)
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write = 0;
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av_free_packet(&pktl->pkt);
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mp3->queue = pktl->next;
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av_freep(&pktl);
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}
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mp3->queue_end = NULL;
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return ret;
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}
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static void mp3_update_xing(AVFormatContext *s)
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{
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MP3Context *mp3 = s->priv_data;
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int i;
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/* replace "Xing" identification string with "Info" for CBR files. */
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if (!mp3->has_variable_bitrate) {
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avio_seek(s->pb, mp3->xing_offset, SEEK_SET);
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ffio_wfourcc(s->pb, "Info");
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}
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avio_seek(s->pb, mp3->xing_offset + 8, SEEK_SET);
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avio_wb32(s->pb, mp3->frames);
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avio_wb32(s->pb, mp3->size);
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avio_w8(s->pb, 0); // first toc entry has to be zero.
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for (i = 1; i < XING_TOC_SIZE; ++i) {
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int j = i * mp3->pos / XING_TOC_SIZE;
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int seek_point = 256LL * mp3->bag[j] / mp3->size;
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avio_w8(s->pb, FFMIN(seek_point, 255));
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}
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avio_seek(s->pb, 0, SEEK_END);
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}
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static int mp3_write_trailer(struct AVFormatContext *s)
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{
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uint8_t buf[ID3v1_TAG_SIZE];
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MP3Context *mp3 = s->priv_data;
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if (mp3->pics_to_write) {
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av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
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"attached pictures.\n");
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mp3_queue_flush(s);
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}
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/* write the id3v1 tag */
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if (mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
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avio_write(s->pb, buf, ID3v1_TAG_SIZE);
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}
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if (mp3->xing_offset)
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mp3_update_xing(s);
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return 0;
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}
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#if CONFIG_MP2_MUXER
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AVOutputFormat ff_mp2_muxer = {
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.name = "mp2",
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.long_name = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
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.mime_type = "audio/x-mpeg",
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.extensions = "mp2,m2a,mpa",
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.audio_codec = AV_CODEC_ID_MP2,
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.video_codec = AV_CODEC_ID_NONE,
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.write_packet = ff_raw_write_packet,
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.flags = AVFMT_NOTIMESTAMPS,
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};
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#endif
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#if CONFIG_MP3_MUXER
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static const AVOption options[] = {
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{ "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
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offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 0, 4, AV_OPT_FLAG_ENCODING_PARAM},
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{ "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
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offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
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{ "write_xing", "Write the Xing header containing file duration.",
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offsetof(MP3Context, write_xing), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
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{ NULL },
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};
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static const AVClass mp3_muxer_class = {
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.class_name = "MP3 muxer",
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.item_name = av_default_item_name,
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.option = options,
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.version = LIBAVUTIL_VERSION_INT,
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};
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static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt)
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{
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MP3Context *mp3 = s->priv_data;
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if (pkt->stream_index == mp3->audio_stream_idx) {
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if (mp3->pics_to_write) {
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/* buffer audio packets until we get all the pictures */
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AVPacketList *pktl = av_mallocz(sizeof(*pktl));
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if (!pktl)
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return AVERROR(ENOMEM);
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pktl->pkt = *pkt;
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pktl->pkt.buf = av_buffer_ref(pkt->buf);
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if (!pktl->pkt.buf) {
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av_freep(&pktl);
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return AVERROR(ENOMEM);
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}
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if (mp3->queue_end)
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mp3->queue_end->next = pktl;
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else
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mp3->queue = pktl;
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mp3->queue_end = pktl;
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} else
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return mp3_write_audio_packet(s, pkt);
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} else {
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int ret;
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/* warn only once for each stream */
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if (s->streams[pkt->stream_index]->nb_frames == 1) {
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av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
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" ignoring.\n", pkt->stream_index);
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}
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if (!mp3->pics_to_write || s->streams[pkt->stream_index]->nb_frames >= 1)
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return 0;
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if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
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return ret;
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mp3->pics_to_write--;
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/* flush the buffered audio packets */
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if (!mp3->pics_to_write &&
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(ret = mp3_queue_flush(s)) < 0)
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return ret;
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}
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return 0;
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}
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/**
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* Write an ID3v2 header at beginning of stream
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*/
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static int mp3_write_header(struct AVFormatContext *s)
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{
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MP3Context *mp3 = s->priv_data;
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int ret, i;
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if (mp3->id3v2_version &&
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mp3->id3v2_version != 3 &&
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mp3->id3v2_version != 4) {
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av_log(s, AV_LOG_ERROR, "Invalid ID3v2 version requested: %d. Only "
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"3, 4 or 0 (disabled) are allowed.\n", mp3->id3v2_version);
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return AVERROR(EINVAL);
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}
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/* check the streams -- we want exactly one audio and arbitrary number of
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* video (attached pictures) */
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mp3->audio_stream_idx = -1;
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for (i = 0; i < s->nb_streams; i++) {
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AVStream *st = s->streams[i];
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if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
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if (mp3->audio_stream_idx >= 0 || st->codec->codec_id != AV_CODEC_ID_MP3) {
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av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
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"audio stream is required.\n");
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return AVERROR(EINVAL);
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}
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mp3->audio_stream_idx = i;
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} else if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) {
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av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
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return AVERROR(EINVAL);
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}
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}
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if (mp3->audio_stream_idx < 0) {
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av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
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return AVERROR(EINVAL);
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}
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mp3->pics_to_write = s->nb_streams - 1;
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if (mp3->pics_to_write && !mp3->id3v2_version) {
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av_log(s, AV_LOG_ERROR, "Attached pictures were requested, but the "
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"ID3v2 header is disabled.\n");
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return AVERROR(EINVAL);
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}
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if (mp3->id3v2_version) {
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ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
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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);
|
|
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/x-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,
|
|
.flags = AVFMT_NOTIMESTAMPS,
|
|
.priv_class = &mp3_muxer_class,
|
|
};
|
|
#endif
|