[FFmpeg-devel] [PATCH 1/7] lavf: add cue sheet demuxer
Nicolas George
george at nsup.org
Tue Aug 1 10:58:49 EEST 2017
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 += ...;
}
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.
(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.
> + }
> +
> + 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.
> + 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", ...).
> + 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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