segment: introduce segmented chain muxer

Initial test code, the filename isn't yet guessed and the file index
isn't printed yet.

libavformat/Makefile

@@ -260,6 +260,7 @@ OBJS-$(CONFIG_SAP_DEMUXER)               += sapdec.o
 OBJS-$(CONFIG_SAP_MUXER)                 += sapenc.o rtpenc_chain.o
 OBJS-$(CONFIG_SDP_DEMUXER)               += rtsp.o
 OBJS-$(CONFIG_SEGAFILM_DEMUXER)          += segafilm.o
+OBJS-$(CONFIG_SEGMENT_MUXER)          	 += segment.o
 OBJS-$(CONFIG_SHORTEN_DEMUXER)           += rawdec.o
 OBJS-$(CONFIG_SIFF_DEMUXER)              += siff.o
 OBJS-$(CONFIG_SMACKER_DEMUXER)           += smacker.o

libavformat/allformats.c

@@ -194,6 +194,7 @@ void av_register_all(void)
     av_register_rdt_dynamic_payload_handlers();
 #endif
     REGISTER_DEMUXER  (SEGAFILM, segafilm);
+    REGISTER_MUXER    (SEGMENT, segment);
     REGISTER_DEMUXER  (SHORTEN, shorten);
     REGISTER_DEMUXER  (SIFF, siff);
     REGISTER_DEMUXER  (SMACKER, smacker);

libavformat/segment.c

@@ -0,0 +1,220 @@
+/*
+ * Generic Segmenter
+ * Copyright (c) 2011, Luca Barbato
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/parseutils.h"
+#include "avformat.h"
+#include "internal.h"
+#include <strings.h>
+#include <float.h>
+
+typedef struct {
+    const AVClass *class;  /**< Class for private options. */
+    int number;
+    char path[1024];
+    AVFormatContext *avf;
+    char *format;          /**< Set by a private option. */
+    float time;            /**< Set by a private option. */
+    int64_t offset_time;
+    int64_t recording_time;
+} SegmentContext;
+
+#if CONFIG_SEGMENT_MUXER
+
+static int segment_header(SegmentContext *s)
+{
+    AVFormatContext *oc = s->avf;
+    int err = 0;
+
+    av_strlcpy(oc->filename, s->path, sizeof(oc->filename));
+
+    av_strlcatf(oc->filename, sizeof(oc->filename), "%03d", s->number++);
+
+    if ((err = avio_open(&oc->pb, oc->filename, AVIO_FLAG_WRITE)) < 0) {
+        return err;
+    }
+
+    if (!oc->priv_data && oc->oformat->priv_data_size > 0) {
+        oc->priv_data = av_mallocz(oc->oformat->priv_data_size);
+        if (!oc->priv_data) {
+            avio_close(oc->pb);
+            return AVERROR(ENOMEM);
+        }
+    }
+
+    if ((err = oc->oformat->write_header(oc)) < 0) {
+        avio_close(oc->pb);
+        av_freep(&oc->priv_data);
+    }
+
+    return err;
+}
+
+static int segment_trailer(AVFormatContext *oc)
+{
+    int ret = 0;
+
+    if(oc->oformat->write_trailer)
+        ret = oc->oformat->write_trailer(oc);
+
+    avio_close(oc->pb);
+    av_freep(&oc->priv_data);
+
+    return ret;
+}
+
+static int seg_write_header(AVFormatContext *s)
+{
+    SegmentContext *seg = s->priv_data;
+    AVFormatContext *oc;
+    int ret;
+
+    seg->number = 0;
+    seg->recording_time = seg->time*1000000;
+    seg->offset_time = 0;
+
+    av_strlcpy(seg->path, "test", sizeof("test"));
+
+    oc = avformat_alloc_context();
+
+    if (!oc) {
+        return AVERROR(ENOMEM);
+    }
+
+    oc->oformat = av_guess_format(seg->format, NULL, NULL);
+
+    if (!oc->oformat) {
+        avformat_free_context(oc);
+        return AVERROR_MUXER_NOT_FOUND;
+    }
+
+    seg->avf = oc;
+
+    oc->streams = s->streams;
+    oc->nb_streams = s->nb_streams;
+
+    av_strlcpy(oc->filename, seg->path, sizeof(oc->filename));
+
+    av_strlcatf(oc->filename, sizeof(oc->filename), "%2d", seg->number++);
+
+    if ((ret = avio_open(&oc->pb, oc->filename, AVIO_FLAG_WRITE)) < 0) {
+        avformat_free_context(oc);
+        return ret;
+    }
+
+    if ((ret = avformat_write_header(oc, NULL)) < 0) {
+        avio_close(oc->pb);
+    }
+
+    if (ret)
+        avformat_free_context(oc);
+
+    return ret;
+}
+
+static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    SegmentContext *seg = s->priv_data;
+    AVFormatContext *oc = seg->avf;
+    AVStream *st = oc->streams[pkt->stream_index];
+    int ret;
+
+    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
+        av_compare_ts(pkt->pts, st->time_base,
+                  seg->recording_time*seg->number,
+                              (AVRational){1, 1000000}) >= 0 &&
+        pkt->flags & AV_PKT_FLAG_KEY) {
+        av_log(s, AV_LOG_INFO, "I'd reset at %d %"PRId64"\n",
+               pkt->stream_index, pkt->pts);
+
+        ret = segment_trailer(oc);
+        if (!ret)
+            ret = segment_header(seg);
+
+        if (ret) {
+            avformat_free_context(oc);
+            return ret;
+        }
+
+    }
+
+    ret = oc->oformat->write_packet(oc, pkt);
+
+    return ret;
+}
+
+static int seg_write_trailer(struct AVFormatContext *s)
+{
+    SegmentContext *seg = s->priv_data;
+    AVFormatContext *oc = seg->avf;
+
+    return segment_trailer(oc);
+}
+
+#endif /* CONFIG_SEGMENT_MUXER */
+
+#define OFFSET(x) offsetof(SegmentContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "container_format", "container format used for the segments", OFFSET(format), FF_OPT_TYPE_STRING, {.str = "nut"}, 0, 0, E },
+    { "segment_time",     "segment lenght in seconds",              OFFSET(time),     FF_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E },
+    { NULL },
+};
+
+static const AVClass seg_class = {
+    .class_name = "segment muxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+/* input
+#if CONFIG_IMAGE2_DEMUXER
+AVInputFormat ff_image2_demuxer = {
+    .name           = "image2",
+    .long_name      = NULL_IF_CONFIG_SMALL("image2 sequence"),
+    .priv_data_size = sizeof(VideoData),
+    .read_probe     = read_probe,
+    .read_header    = read_header,
+    .read_packet    = read_packet,
+    .flags          = AVFMT_NOFILE,
+    .priv_class     = &img2_class,
+};
+#endif
+*/
+
+/* output */
+#if CONFIG_SEGMENT_MUXER
+AVOutputFormat ff_segment_muxer = {
+    .name           = "segment",
+    .long_name      = NULL_IF_CONFIG_SMALL("segment muxer"),
+    .extensions     = "m3u8",
+    .priv_data_size = sizeof(SegmentContext),
+    .flags          = AVFMT_GLOBALHEADER,
+    .write_header   = seg_write_header,
+    .write_packet   = seg_write_packet,
+    .write_trailer  = seg_write_trailer,
+    .priv_class     = &seg_class,
+};
+#endif