[FFmpeg-devel] [PATCH 1/7] lavf: add cue sheet demuxer
Rodger Combs
rodger.combs at gmail.com
Wed Aug 2 09:28:16 EEST 2017
> On Aug 1, 2017, at 02:58, Nicolas George <george at nsup.org> wrote:
>
> Le quartidi 14 thermidor, an CCXXV, Rodger Combs a écrit :
>> ---
>> Changelog | 2 +
>> doc/demuxers.texi | 8 ++
>> libavformat/Makefile | 1 +
>> libavformat/allformats.c | 1 +
>> libavformat/cuedec.c | 215 +++++++++++++++++++++++++++++++++++++++++++++++
>> libavformat/version.h | 2 +-
>> 6 files changed, 228 insertions(+), 1 deletion(-)
>> create mode 100644 libavformat/cuedec.c
>>
>> diff --git a/Changelog b/Changelog
>> index 187ae79..6701d30 100644
>> --- a/Changelog
>> +++ b/Changelog
>> @@ -29,6 +29,8 @@ version <next>:
>> - limiter video filter
>> - libvmaf video filter
>> - Dolby E decoder and SMPTE 337M demuxer
>> +- Cue sheet demuxer
>> +
>>
>> version 3.3:
>> - CrystalHD decoder moved to new decode API
>> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
>> index 29a23d4..7ea4f27 100644
>> --- a/doc/demuxers.texi
>> +++ b/doc/demuxers.texi
>> @@ -244,6 +244,14 @@ file subdir/file-2.wav
>> @end example
>> @end itemize
>>
>> + at section cue
>> +
>> +Cue sheet demuxer.
>> +
>> +This demuxer reads a cue sheet (text file) and exports its track listing in
>> +the form of AVChapters. Packet data is read from the file listed in the sheet.
>> +To override the path the packet data is read from, use the @code{url} option.
>> +
>> @section flv, live_flv
>>
>> Adobe Flash Video Format demuxer.
>> diff --git a/libavformat/Makefile b/libavformat/Makefile
>> index b0ef82c..4381c42 100644
>> --- a/libavformat/Makefile
>> +++ b/libavformat/Makefile
>> @@ -130,6 +130,7 @@ OBJS-$(CONFIG_CDXL_DEMUXER) += cdxl.o
>> OBJS-$(CONFIG_CINE_DEMUXER) += cinedec.o
>> OBJS-$(CONFIG_CONCAT_DEMUXER) += concatdec.o
>> OBJS-$(CONFIG_CRC_MUXER) += crcenc.o
>> +OBJS-$(CONFIG_CUE_DEMUXER) += cuedec.o
>> OBJS-$(CONFIG_DATA_DEMUXER) += rawdec.o
>> OBJS-$(CONFIG_DATA_MUXER) += rawenc.o
>> OBJS-$(CONFIG_DASH_MUXER) += dashenc.o
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index 1ebc142..25afa8b 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -96,6 +96,7 @@ static void register_all(void)
>> REGISTER_DEMUXER (CINE, cine);
>> REGISTER_DEMUXER (CONCAT, concat);
>> REGISTER_MUXER (CRC, crc);
>> + REGISTER_DEMUXER (CUE, cue);
>> REGISTER_MUXER (DASH, dash);
>> REGISTER_MUXDEMUX(DATA, data);
>> REGISTER_MUXDEMUX(DAUD, daud);
>> diff --git a/libavformat/cuedec.c b/libavformat/cuedec.c
>> new file mode 100644
>> index 0000000..d0dcac4
>> --- /dev/null
>> +++ b/libavformat/cuedec.c
>> @@ -0,0 +1,215 @@
>> +/*
>> + * Cue sheet demuxer
>> + * Copyright (c) 2016 The FFmpeg Project
>> + *
>> + * 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
>> + * Cue sheet demuxer
>> + * @author Rodger Combs <rodger.combs at gmail.com>
>> + */
>> +
>> +#include "avformat.h"
>> +#include "internal.h"
>> +#include "subtitles.h"
>> +#include "url.h"
>> +#include "libavutil/intreadwrite.h"
>> +#include "libavutil/avstring.h"
>> +#include "libavutil/opt.h"
>> +
>> +typedef struct CueDemuxContext {
>> + AVClass *class;
>> + char *url;
>> + AVFormatContext *avf;
>> +} CueDemuxContext;
>> +
>> +static int cue_probe(AVProbeData *p)
>> +{
>> + const unsigned char *ptr = p->buf;
>> +
>> + if (AV_RB24(ptr) == 0xEFBBBF)
>> + ptr += 3; /* skip UTF-8 BOM */
>
>> + while (*ptr && strncmp(ptr, "FILE ", 5))
>> + ptr += ff_subtitles_next_line(ptr);
>> + if (!strncmp(ptr, "FILE ", 5))
>> + return AVPROBE_SCORE_MAX - 5;
>
> The duplicated test feels inelegant to me. Better:
>
> while (*ptr) {
> if (strncmp(...))
> return ...;
> ptr += ...;
> }
Moving in the direction of this format in my new version.
>
> Also, this code matches any text file with a line starting with the word
> FILE near the beginning. In other words, it would recognize this very
> mail as a cue sheet! I think it needs to be stricter: at least FILE
> followed by spaces and a double quote and "TRACK ?? AUDIO" later.
Done.
>
> (It would be nice to have a built-in regex compiler that would combine
> all similar probe functions into a single finite-state machine.)
>
>> + return 0;
>> +}
>> +
>> +static char *get_token(char *in)
>> +{
>> + char *end;
>> + while (av_isspace(*in))
>> + in++;
>> + if (*in == '"') {
>> + in++;
>> + end = in + strcspn(in, "\"\n\t\r");
>> + } else {
>> + end = in + strcspn(in, " \n\t\r");
>> + }
>> + *end = '\0';
>> + return in;
>> +}
>> +
>> +static int cue_read_header(AVFormatContext *s)
>> +{
>> + int ret, i;
>> + CueDemuxContext *cue = s->priv_data;
>> + char line[4096], *ptr;
>> + AVDictionary **meta = &s->metadata;
>> + AVChapter *chap = NULL;
>> + while (ff_get_line(s->pb, line, sizeof(line))) {
>> + ptr = line;
>> + if (AV_RB24(ptr) == 0xEFBBBF)
>> + ptr += 3; /* skip UTF-8 BOM */
>> + while (*ptr == ' ' || *ptr == '\t')
>> + ptr++;
>> + if (!strncmp(ptr, "REM ", 4)) {
>> + char *end = ptr + strcspn(ptr, "\r\n");
>> + *end = '\0';
>> + av_log(s, AV_LOG_INFO, "Comment: \"%s\"\n", ptr + 4);
>> + } else if (!strncmp(ptr, "TITLE ", 6)) {
>> + ptr = get_token(ptr + 6);
>> + av_dict_set(meta, chap ? "title" : "album", ptr, 0);
>> + } else if (!strncmp(ptr, "PERFORMER ", 10)) {
>> + ptr = get_token(ptr + 10);
>> + av_dict_set(meta, chap ? "artist" : "album_artist", ptr, 0);
>> + } else if (!strncmp(ptr, "FILE ", 5)) {
>> + if (!cue->url || !*cue->url) {
>> + const char *filename = get_token(ptr + 5);
>> + char url[4096] = {0};
>> +
>> + if (filename[strcspn(filename, "/\\:")] != 0) {
>> + av_log(s, AV_LOG_ERROR, "Only bare filenames are allowed in cue FILE directives.\n"
>> + "To read from '%s', use the 'url' option explicitly.", filename);
>
>> + return AVERROR_INVALIDDATA;
>
> AVERROR(EPERM)? Like in concat and hls.
Done.
>
>> + }
>> +
>> + av_freep(&cue->url);
>> + ff_make_absolute_url(url, sizeof(url), s->filename, filename);
>
>> + if (!(cue->url = av_strdup(url)))
>
> If the condition above was met because of !cue->url, then it is ok, but
> if it was !*cue->url, then this is leaking.
Note the preceding av_freep().
>
>> + return AVERROR(ENOMEM);
>> + }
>> + } else if (!strncmp(ptr, "TRACK ", 6)) {
>> + int index = strtol(ptr + 6, &ptr, 10);
>> + chap = avpriv_new_chapter(s, index, (AVRational){1, 75}, AV_NOPTS_VALUE, AV_NOPTS_VALUE, NULL);
>> + if (!chap)
>> + return AVERROR(ENOMEM);
>> + meta = &chap->metadata;
>> + if ((ret = av_dict_copy(meta, s->metadata, 0)) < 0)
>> + return ret;
>> + av_dict_set_int(meta, "track", index, 0);
>> + } else if (!strncmp(ptr, "INDEX ", 6)) {
>> + int min, sec, frame;
>
>> + int index = strtol(ptr + 6, &ptr, 10);
>> + if (!chap)
>> + return AVERROR_INVALIDDATA;
>> + if (sscanf(ptr, "%u:%u:%u", &min, &sec, &frame) != 3)
>> + return AVERROR_INVALIDDATA;
>
> You can combine the strtol() and sscanf() into a single sscanf():
> sscanf(ptr, "%u %u:%u:%u", ...).
Done.
>
>> + if (index == 1 || chap->start == 0)
>> + chap->start = min * 75 * 60 + sec * 75 + frame;
>> + } else {
>> + av_log(s, AV_LOG_WARNING, "Unknown command: \"%s\"\n", ptr);
>> + }
>> + }
>> +
>> + if (!cue->url || !*cue->url)
>> + return AVERROR_INVALIDDATA;
>> +
>> + if (!(cue->avf = avformat_alloc_context()))
>> + return AVERROR(ENOMEM);
>> +
>> + cue->avf->interrupt_callback = s->interrupt_callback;
>> + if ((ret = ff_copy_whiteblacklists(cue->avf, s)) < 0)
>> + return ret;
>> +
>> + if ((ret = avformat_open_input(&cue->avf, cue->url, NULL, NULL)) < 0 ||
>> + (ret = avformat_find_stream_info(cue->avf, NULL)) < 0) {
>> + av_log(s, AV_LOG_ERROR, "Failed to open '%s'\n", cue->url);
>> + avformat_close_input(&cue->avf);
>> + return ret;
>> + }
>> +
>> + ff_read_frame_flush(cue->avf);
>> +
>> + for (i = 0; i < cue->avf->nb_streams; i++) {
>> + AVStream *st = avformat_new_stream(s, NULL);
>> + AVStream *ist = cue->avf->streams[i];
>> + if (!st)
>> + return AVERROR(ENOMEM);
>> + st->id = i;
>> +
>> + avcodec_parameters_copy(st->codecpar, ist->codecpar);
>> +
>> + st->disposition = ist->disposition;
>> + avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
>> + av_copy_packet(&st->attached_pic, &ist->attached_pic);
>> + }
>> +
>> + s->duration = cue->avf->duration;
>> +
>> + return 0;
>> +}
>> +
>> +static int cue_read_packet(AVFormatContext *s, AVPacket *pkt)
>> +{
>> + CueDemuxContext *cue = s->priv_data;
>> + return av_read_frame(cue->avf, pkt);
>> +}
>> +
>> +static int cue_read_seek(AVFormatContext *s, int stream_index,
>> + int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
>> +{
>> + CueDemuxContext *cue = s->priv_data;
>> + return avformat_seek_file(cue->avf, stream_index, min_ts, ts, max_ts, flags);
>> +}
>> +
>> +static int cue_read_close(AVFormatContext *s)
>> +{
>> + CueDemuxContext *cue = s->priv_data;
>> + avformat_close_input(&cue->avf);
>> + return 0;
>> +}
>> +
>> +#define OFFSET(x) offsetof(CueDemuxContext, x)
>> +#define E AV_OPT_FLAG_DECODING_PARAM
>> +static const AVOption options[] = {
>> + { "url", "override underlying audio location", OFFSET(url), AV_OPT_TYPE_STRING, {.str = ""}, CHAR_MIN, CHAR_MAX, E },
>> + { NULL }
>> +};
>> +
>> +static const AVClass cue_class = {
>> + .class_name = "Cue sheet demuxer",
>> + .item_name = av_default_item_name,
>> + .option = options,
>> + .version = LIBAVUTIL_VERSION_INT,
>> +};
>> +
>> +AVInputFormat ff_cue_demuxer = {
>> + .name = "cue",
>> + .long_name = NULL_IF_CONFIG_SMALL("Cue sheet"),
>> + .extensions = "cue",
>> + .priv_data_size = sizeof(CueDemuxContext),
>> + .read_probe = cue_probe,
>> + .read_header = cue_read_header,
>> + .read_packet = cue_read_packet,
>> + .read_seek2 = cue_read_seek,
>> + .read_close = cue_read_close,
>> + .priv_class = &cue_class,
>> +};
>> diff --git a/libavformat/version.h b/libavformat/version.h
>> index 48b81f2..a8cf4c1 100644
>> --- a/libavformat/version.h
>> +++ b/libavformat/version.h
>> @@ -32,7 +32,7 @@
>> // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
>> // Also please add any ticket numbers that you believe might be affected here
>> #define LIBAVFORMAT_VERSION_MAJOR 57
>> -#define LIBAVFORMAT_VERSION_MINOR 76
>> +#define LIBAVFORMAT_VERSION_MINOR 77
>> #define LIBAVFORMAT_VERSION_MICRO 100
>>
>> #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
>
> Regards,
>
> --
> Nicolas George
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