segment: introduce segmented chain muxer

It behaves similarly to image2 muxer

1 files changed, 273 insertions, 0 deletions

diff --git a/libavformat/segment.c b/libavformat/segment.c
new file mode 100644
index 0000000000..89ae62d312
--- /dev/null
+++ b/libavformat/segment.c
@@ -0,0 +1,273 @@
+/*
+ * 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 <strings.h>
+#include <float.h>
+
+#include "avformat.h"
+#include "internal.h"
+
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+#include "libavutil/avstring.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/mathematics.h"
+
+typedef struct {
+    const AVClass *class;  /**< Class for private options. */
+    int number;
+    AVFormatContext *avf;
+    char *format;          /**< Set by a private option. */
+    char *list;            /**< Set by a private option. */
+    float time;            /**< Set by a private option. */
+    int  size;             /**< Set by a private option. */
+    int64_t offset_time;
+    int64_t recording_time;
+    int has_video;
+    AVIOContext *pb;
+} SegmentContext;
+
+static int segment_start(AVFormatContext *s)
+{
+    SegmentContext *c = s->priv_data;
+    AVFormatContext *oc = c->avf;
+    int err = 0;
+
+    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
+                              s->filename, c->number++) < 0)
+        return AVERROR(EINVAL);
+
+    if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
+                          &s->interrupt_callback, NULL)) < 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 (oc->oformat->priv_class) {
+            *(const AVClass**)oc->priv_data = oc->oformat->priv_class;
+            av_opt_set_defaults(oc->priv_data);
+        }
+    }
+
+    if ((err = oc->oformat->write_header(oc)) < 0) {
+        goto fail;
+    }
+
+    return 0;
+
+fail:
+    avio_close(oc->pb);
+    av_freep(&oc->priv_data);
+
+    return err;
+}
+
+static int segment_end(AVFormatContext *oc)
+{
+    int ret = 0;
+
+    if (oc->oformat->write_trailer)
+        ret = oc->oformat->write_trailer(oc);
+
+    avio_close(oc->pb);
+    if (oc->oformat->priv_class)
+        av_opt_free(oc->priv_data);
+    av_freep(&oc->priv_data);
+
+    return ret;
+}
+
+static int seg_write_header(AVFormatContext *s)
+{
+    SegmentContext *seg = s->priv_data;
+    AVFormatContext *oc;
+    int ret, i;
+
+    seg->number = 0;
+    seg->offset_time = 0;
+    seg->recording_time = seg->time * 1000000;
+
+    if (seg->list)
+        if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
+                              &s->interrupt_callback, NULL)) < 0)
+            return ret;
+
+    for (i = 0; i< s->nb_streams; i++)
+        seg->has_video +=
+            (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO);
+
+    if (seg->has_video > 1)
+        av_log(s, AV_LOG_WARNING,
+               "More than a single video stream present, "
+               "expect issues decoding it.\n");
+
+    oc = avformat_alloc_context();
+
+    if (!oc) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    oc->oformat = av_guess_format(seg->format, s->filename, NULL);
+
+    if (!oc->oformat) {
+        ret = AVERROR_MUXER_NOT_FOUND;
+        goto fail;
+    }
+    if (oc->oformat->flags & AVFMT_NOFILE) {
+        av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
+               oc->oformat->name);
+        ret = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    seg->avf = oc;
+
+    oc->streams = s->streams;
+    oc->nb_streams = s->nb_streams;
+
+    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
+                              s->filename, seg->number++) < 0) {
+        ret = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
+                          &s->interrupt_callback, NULL)) < 0)
+        goto fail;
+
+    if ((ret = avformat_write_header(oc, NULL)) < 0) {
+        avio_close(oc->pb);
+        goto fail;
+    }
+
+    if (seg->list) {
+        avio_printf(seg->pb, "%s\n", oc->filename);
+        avio_flush(seg->pb);
+    }
+
+fail:
+    if (ret) {
+        oc->streams = NULL;
+        oc->nb_streams = 0;
+        if (seg->list)
+            avio_close(seg->pb);
+        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];
+    int64_t end_pts = seg->recording_time * seg->number;
+    int ret;
+
+    if ((seg->has_video && st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
+        av_compare_ts(pkt->pts, st->time_base,
+                      end_pts, AV_TIME_BASE_Q) >= 0 &&
+        pkt->flags & AV_PKT_FLAG_KEY) {
+
+        av_log(s, AV_LOG_DEBUG, "Next segment starts at %d %"PRId64"\n",
+               pkt->stream_index, pkt->pts);
+
+        ret = segment_end(oc);
+
+        if (!ret)
+            ret = segment_start(s);
+
+        if (ret)
+            goto fail;
+
+        if (seg->list) {
+            avio_printf(seg->pb, "%s\n", oc->filename);
+            avio_flush(seg->pb);
+            if (!(seg->number % seg->size)) {
+                avio_close(seg->pb);
+                if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
+                                      &s->interrupt_callback, NULL)) < 0)
+                    goto fail;
+
+            }
+        }
+    }
+
+    ret = oc->oformat->write_packet(oc, pkt);
+
+fail:
+    if (ret < 0) {
+        oc->streams = NULL;
+        oc->nb_streams = 0;
+        if (seg->list)
+            avio_close(seg->pb);
+        avformat_free_context(oc);
+    }
+
+    return ret;
+}
+
+static int seg_write_trailer(struct AVFormatContext *s)
+{
+    SegmentContext *seg = s->priv_data;
+    AVFormatContext *oc = seg->avf;
+    int ret = segment_end(oc);
+    if (seg->list)
+        avio_close(seg->pb);
+    oc->streams = NULL;
+    oc->nb_streams = 0;
+    avformat_free_context(oc);
+    return ret;
+}
+
+#define OFFSET(x) offsetof(SegmentContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "segment_format",    "container format used for the segments",  OFFSET(format),  AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
+    { "segment_time",      "segment length in seconds",               OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E },
+    { "segment_list",      "output the segment list",                 OFFSET(list),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
+    { "segment_list_size", "maximum number of playlist entries",      OFFSET(size),    AV_OPT_TYPE_INT,    {.dbl = 5},     0, INT_MAX, E },
+    { NULL },
+};
+
+static const AVClass seg_class = {
+    .class_name = "segment muxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+
+AVOutputFormat ff_segment_muxer = {
+    .name           = "segment",
+    .long_name      = NULL_IF_CONFIG_SMALL("segment muxer"),
+    .priv_data_size = sizeof(SegmentContext),
+    .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
+    .write_header   = seg_write_header,
+    .write_packet   = seg_write_packet,
+    .write_trailer  = seg_write_trailer,
+    .priv_class     = &seg_class,
+};