hlsenc: stand alone hls segmenter

Simplifies usage but has higher latency.

1 files changed, 324 insertions, 0 deletions

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
new file mode 100644
index 0000000000..88f47e0f37
--- /dev/null
+++ b/libavformat/hlsenc.c
@@ -0,0 +1,324 @@
+/*
+ * Apple HTTP Live Streaming segmenter
+ * Copyright (c) 2012, 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 <float.h>
+
+#include "libavutil/mathematics.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "libavutil/log.h"
+
+#include "avformat.h"
+#include "internal.h"
+
+typedef struct ListEntry {
+    char  name[1024];
+    int   duration;
+    struct ListEntry *next;
+} ListEntry;
+
+typedef struct HLSContext {
+    const AVClass *class;  // Class for private options.
+    int number;
+    AVOutputFormat *oformat;
+    AVFormatContext *avf;
+    float time;            // Set by a private option.
+    int  size;             // Set by a private option.
+    int  wrap;             // Set by a private option.
+    int64_t recording_time;
+    int has_video;
+    int64_t start_pts;
+    int64_t end_pts;
+    ListEntry *list;
+    ListEntry *end_list;
+    char *basename;
+    AVIOContext *pb;
+} HLSContext;
+
+static int hls_mux_init(AVFormatContext *s)
+{
+    HLSContext *hls = s->priv_data;
+    AVFormatContext *oc;
+    int i;
+
+    hls->avf = oc = avformat_alloc_context();
+    if (!oc)
+        return AVERROR(ENOMEM);
+
+    oc->oformat            = hls->oformat;
+    oc->interrupt_callback = s->interrupt_callback;
+
+    for (i = 0; i < s->nb_streams; i++) {
+        AVStream *st;
+        if (!(st = avformat_new_stream(oc, NULL)))
+            return AVERROR(ENOMEM);
+        avcodec_copy_context(st->codec, s->streams[i]->codec);
+        st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
+    }
+
+    return 0;
+}
+
+static int append_entry(HLSContext *hls, uint64_t duration)
+{
+    ListEntry *en = av_malloc(sizeof(*en));
+
+    if (!en)
+        return AVERROR(ENOMEM);
+
+    av_get_frame_filename(en->name, sizeof(en->name), hls->basename,
+                          hls->number -1);
+
+    en->duration = duration;
+    en->next     = NULL;
+
+    if (!hls->list)
+        hls->list = en;
+    else
+        hls->end_list->next = en;
+
+    hls->end_list = en;
+
+    if (hls->number >= hls->size) {
+        en = hls->list;
+        hls->list = en->next;
+        av_free(en);
+    }
+
+    return 0;
+}
+
+static void free_entries(HLSContext *hls)
+{
+    ListEntry *p = hls->list, *en;
+
+    while(p) {
+        en = p;
+        p = p->next;
+        av_free(en);
+    }
+}
+
+static int hls_window(AVFormatContext *s, int last)
+{
+    HLSContext *hls = s->priv_data;
+    ListEntry *en;
+    int ret = 0;
+
+    if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
+                          &s->interrupt_callback, NULL)) < 0)
+        goto fail;
+
+    avio_printf(hls->pb, "#EXTM3U\n");
+    avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
+    avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", (int)hls->time);
+    avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%d\n",
+                FFMAX(0, hls->number - hls->size));
+
+    for (en = hls->list; en; en = en->next) {
+        avio_printf(hls->pb, "#EXTINF:%d,\n", en->duration);
+        avio_printf(hls->pb, "%s\n", en->name);
+    }
+
+    if (last)
+        avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
+
+fail:
+    avio_closep(&hls->pb);
+    return ret;
+}
+
+static int hls_start(AVFormatContext *s)
+{
+    HLSContext *c = s->priv_data;
+    AVFormatContext *oc = c->avf;
+    int err = 0;
+
+    if (c->wrap)
+        c->number %= c->wrap;
+
+    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
+                              c->basename, 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->oformat->priv_class && oc->priv_data)
+        av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
+
+    return 0;
+}
+
+static int hls_write_header(AVFormatContext *s)
+{
+    HLSContext *hls = s->priv_data;
+    int ret, i;
+    char *p;
+    const char *pattern = "%d.ts";
+    int basename_size = strlen(s->filename) + strlen(pattern);
+
+    hls->number      = 0;
+
+    hls->recording_time = hls->time * 1000000;
+    hls->start_pts      = AV_NOPTS_VALUE;
+
+    for (i = 0; i < s->nb_streams; i++)
+        hls->has_video +=
+            s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO;
+
+    if (hls->has_video > 1)
+        av_log(s, AV_LOG_WARNING,
+               "More than a single video stream present, "
+               "expect issues decoding it.\n");
+
+    hls->oformat = av_guess_format("mpegts", NULL, NULL);
+
+    if (!hls->oformat) {
+        ret = AVERROR_MUXER_NOT_FOUND;
+        goto fail;
+    }
+
+    hls->basename = av_malloc(basename_size);
+
+    if (!hls->basename) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    strcpy(hls->basename, s->filename);
+
+    p = strrchr(hls->basename, '.');
+
+    if (p)
+        *p = '\0';
+
+    av_strlcat(hls->basename, "%d.ts", basename_size);
+
+    if ((ret = hls_mux_init(s)) < 0)
+        goto fail;
+
+    if ((ret = hls_start(s)) < 0)
+        goto fail;
+
+    if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
+        return ret;
+
+
+fail:
+    if (ret) {
+        av_free(hls->basename);
+        if (hls->avf)
+            avformat_free_context(hls->avf);
+    }
+    return ret;
+}
+
+static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    HLSContext *hls = s->priv_data;
+    AVFormatContext *oc = hls->avf;
+    AVStream *st = s->streams[pkt->stream_index];
+    int64_t end_pts = hls->recording_time * hls->number;
+    int ret;
+
+    if (hls->start_pts == AV_NOPTS_VALUE) {
+        hls->start_pts = pkt->pts;
+        hls->end_pts   = pkt->pts;
+    }
+    end_pts += hls->start_pts;
+
+    if ((hls->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) {
+
+        append_entry(hls, av_rescale(pkt->pts - hls->end_pts,
+                                     st->time_base.num,
+                                     st->time_base.den));
+        hls->end_pts = pkt->pts;
+
+        av_write_frame(oc, NULL); /* Flush any buffered data */
+        avio_close(oc->pb);
+
+        ret = hls_start(s);
+
+        if (ret)
+            return ret;
+
+        oc = hls->avf;
+
+        if ((ret = hls_window(s, 0)) < 0)
+            return ret;
+    }
+
+    ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
+
+    return ret;
+}
+
+static int hls_write_trailer(struct AVFormatContext *s)
+{
+    HLSContext *hls = s->priv_data;
+    AVFormatContext *oc = hls->avf;
+
+    av_write_trailer(oc);
+    avio_closep(&oc->pb);
+    avformat_free_context(oc);
+    av_free(hls->basename);
+    hls_window(s, 1);
+
+    free_entries(hls);
+    avio_close(hls->pb);
+    return 0;
+}
+
+#define OFFSET(x) offsetof(HLSContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    {"hls_time",      "segment length in seconds",               OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},
+    {"hls_list_size", "maximum number of playlist entries",      OFFSET(size),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX, E},
+    {"hls_wrap",      "number after which the index wraps",      OFFSET(wrap),    AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E},
+    { NULL },
+};
+
+static const AVClass hls_class = {
+    .class_name = "hls muxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+
+AVOutputFormat ff_hls_muxer = {
+    .name           = "hls",
+    .long_name      = NULL_IF_CONFIG_SMALL("hls"),
+    .extensions     = "m3u8",
+    .priv_data_size = sizeof(HLSContext),
+    .audio_codec    = AV_CODEC_ID_MP2,
+    .video_codec    = AV_CODEC_ID_MPEG2VIDEO,
+    .flags          = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
+    .write_header   = hls_write_header,
+    .write_packet   = hls_write_packet,
+    .write_trailer  = hls_write_trailer,
+    .priv_class     = &hls_class,
+};