Add an HDS live fragmenting muxer

HDS fragments basically are FLV fragments wrapped in an ISO
media mdat atom.

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 589 insertions, 0 deletions

diff --git a/libavformat/hdsenc.c b/libavformat/hdsenc.c
new file mode 100644
index 0000000000..6d5b127a7c
--- /dev/null
+++ b/libavformat/hdsenc.c
@@ -0,0 +1,589 @@
+/*
+ * Live HDS fragmenter
+ * Copyright (c) 2013 Martin Storsjo
+ *
+ * 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 "config.h"
+#include <float.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "avformat.h"
+#include "internal.h"
+#include "os_support.h"
+
+#include "libavutil/avstring.h"
+#include "libavutil/base64.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/opt.h"
+
+typedef struct Fragment {
+    char file[1024];
+    int64_t start_time, duration;
+    int n;
+} Fragment;
+
+typedef struct OutputStream {
+    int bitrate;
+    int first_stream;
+    AVFormatContext *ctx;
+    int ctx_inited;
+    uint8_t iobuf[32768];
+    char temp_filename[1024];
+    int64_t frag_start_ts, last_ts;
+    AVIOContext *out;
+    int packets_written;
+    int nb_fragments, fragments_size, fragment_index;
+    Fragment **fragments;
+
+    int has_audio, has_video;
+
+    uint8_t *metadata;
+    int metadata_size;
+
+    uint8_t *extra_packets[2];
+    int extra_packet_sizes[2];
+    int nb_extra_packets;
+} OutputStream;
+
+typedef struct HDSContext {
+    const AVClass *class;  /* Class for private options. */
+    int window_size;
+    int extra_window_size;
+    int min_frag_duration;
+    int remove_at_exit;
+
+    OutputStream *streams;
+    int nb_streams;
+} HDSContext;
+
+static int parse_header(OutputStream *os, const uint8_t *buf, int buf_size)
+{
+    if (buf_size < 13)
+        return AVERROR_INVALIDDATA;
+    if (memcmp(buf, "FLV", 3))
+        return AVERROR_INVALIDDATA;
+    buf      += 13;
+    buf_size -= 13;
+    while (buf_size >= 11 + 4) {
+        int type = buf[0];
+        int size = AV_RB24(&buf[1]) + 11 + 4;
+        if (size > buf_size)
+            return AVERROR_INVALIDDATA;
+        if (type == 8 || type == 9) {
+            if (os->nb_extra_packets > FF_ARRAY_ELEMS(os->extra_packets))
+                return AVERROR_INVALIDDATA;
+            os->extra_packet_sizes[os->nb_extra_packets] = size;
+            os->extra_packets[os->nb_extra_packets] = av_malloc(size);
+            if (!os->extra_packets[os->nb_extra_packets])
+                return AVERROR(ENOMEM);
+            memcpy(os->extra_packets[os->nb_extra_packets], buf, size);
+            os->nb_extra_packets++;
+        } else if (type == 0x12) {
+            if (os->metadata)
+                return AVERROR_INVALIDDATA;
+            os->metadata_size = size - 11 - 4;
+            os->metadata      = av_malloc(os->metadata_size);
+            if (!os->metadata)
+                return AVERROR(ENOMEM);
+            memcpy(os->metadata, buf + 11, os->metadata_size);
+        }
+        buf      += size;
+        buf_size -= size;
+    }
+    if (!os->metadata)
+        return AVERROR_INVALIDDATA;
+    return 0;
+}
+
+static int hds_write(void *opaque, uint8_t *buf, int buf_size)
+{
+    OutputStream *os = opaque;
+    if (os->out) {
+        avio_write(os->out, buf, buf_size);
+    } else {
+        if (!os->metadata_size) {
+            int ret;
+            // Assuming the IO buffer is large enough to fit the
+            // FLV header and all metadata and extradata packets
+            if ((ret = parse_header(os, buf, buf_size)) < 0)
+                return ret;
+        }
+    }
+    return buf_size;
+}
+
+static void hds_free(AVFormatContext *s)
+{
+    HDSContext *c = s->priv_data;
+    int i, j;
+    if (!c->streams)
+        return;
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        if (os->out)
+            avio_close(os->out);
+        os->out = NULL;
+        if (os->ctx && os->ctx_inited)
+            av_write_trailer(os->ctx);
+        if (os->ctx && os->ctx->pb)
+            av_free(os->ctx->pb);
+        if (os->ctx)
+            avformat_free_context(os->ctx);
+        av_free(os->metadata);
+        for (j = 0; j < os->nb_extra_packets; j++)
+            av_free(os->extra_packets[j]);
+        for (j = 0; j < os->nb_fragments; j++)
+            av_free(os->fragments[j]);
+        av_free(os->fragments);
+    }
+    av_freep(&c->streams);
+}
+
+static int write_manifest(AVFormatContext *s, int final)
+{
+    HDSContext *c = s->priv_data;
+    AVIOContext *out;
+    char filename[1024], temp_filename[1024];
+    int ret, i;
+    float duration = 0;
+
+    if (c->nb_streams > 0)
+        duration = c->streams[0].last_ts * av_q2d(s->streams[0]->time_base);
+
+    snprintf(filename, sizeof(filename), "%s/index.f4m", s->filename);
+    snprintf(temp_filename, sizeof(temp_filename), "%s/index.f4m.tmp", s->filename);
+    ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE,
+                     &s->interrupt_callback, NULL);
+    if (ret < 0) {
+        av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", filename);
+        return ret;
+    }
+    avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
+    avio_printf(out, "<manifest xmlns=\"http://ns.adobe.com/f4m/1.0\">\n");
+    avio_printf(out, "\t<id>%s</id>\n", av_basename(s->filename));
+    avio_printf(out, "\t<streamType>%s</streamType>\n",
+                     final ? "recorded" : "live");
+    avio_printf(out, "\t<deliveryType>streaming</deliveryType>\n");
+    if (final)
+        avio_printf(out, "\t<duration>%f</duration>\n", duration);
+    for (i = 0; i < c->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        int b64_size = AV_BASE64_SIZE(os->metadata_size);
+        char *base64 = av_malloc(b64_size);
+        if (!base64) {
+            avio_close(out);
+            return AVERROR(ENOMEM);
+        }
+        av_base64_encode(base64, b64_size, os->metadata, os->metadata_size);
+
+        avio_printf(out, "\t<bootstrapInfo profile=\"named\" url=\"stream%d.abst\" id=\"bootstrap%d\" />\n", i, i);
+        avio_printf(out, "\t<media bitrate=\"%d\" url=\"stream%d\" bootstrapInfoId=\"bootstrap%d\">\n", os->bitrate/1000, i, i);
+        avio_printf(out, "\t\t<metadata>%s</metadata>\n", base64);
+        avio_printf(out, "\t</media>\n");
+        av_free(base64);
+    }
+    avio_printf(out, "</manifest>\n");
+    avio_flush(out);
+    avio_close(out);
+    rename(temp_filename, filename);
+    return 0;
+}
+
+static void update_size(AVIOContext *out, int64_t pos)
+{
+    int64_t end = avio_tell(out);
+    avio_seek(out, pos, SEEK_SET);
+    avio_wb32(out, end - pos);
+    avio_seek(out, end, SEEK_SET);
+}
+
+/* Note, the .abst files need to be served with the "binary/octet"
+ * mime type, otherwise at least the OSMF player can easily fail
+ * with "stream not found" when polling for the next fragment. */
+static int write_abst(AVFormatContext *s, OutputStream *os, int final)
+{
+    HDSContext *c = s->priv_data;
+    AVIOContext *out;
+    char filename[1024], temp_filename[1024];
+    int i, ret;
+    int64_t asrt_pos, afrt_pos;
+    int start = 0, fragments;
+    int index = s->streams[os->first_stream]->id;
+    int64_t cur_media_time = 0;
+    if (c->window_size)
+        start = FFMAX(os->nb_fragments - c->window_size, 0);
+    fragments = os->nb_fragments - start;
+    if (final)
+        cur_media_time = os->last_ts;
+    else if (os->nb_fragments)
+        cur_media_time = os->fragments[os->nb_fragments - 1]->start_time;
+
+    snprintf(filename, sizeof(filename),
+             "%s/stream%d.abst", s->filename, index);
+    snprintf(temp_filename, sizeof(temp_filename),
+             "%s/stream%d.abst.tmp", s->filename, index);
+    ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE,
+                     &s->interrupt_callback, NULL);
+    if (ret < 0) {
+        av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
+        return ret;
+    }
+    avio_wb32(out, 0); // abst size
+    avio_wl32(out, MKTAG('a','b','s','t'));
+    avio_wb32(out, 0); // version + flags
+    avio_wb32(out, os->fragment_index - 1); // BootstrapinfoVersion
+    avio_w8(out, final ? 0 : 0x20); // profile, live, update
+    avio_wb32(out, 1000); // timescale
+    avio_wb64(out, cur_media_time);
+    avio_wb64(out, 0); // SmpteTimeCodeOffset
+    avio_w8(out, 0); // MovieIdentifer (null string)
+    avio_w8(out, 0); // ServerEntryCount
+    avio_w8(out, 0); // QualityEntryCount
+    avio_w8(out, 0); // DrmData (null string)
+    avio_w8(out, 0); // MetaData (null string)
+    avio_w8(out, 1); // SegmentRunTableCount
+    asrt_pos = avio_tell(out);
+    avio_wb32(out, 0); // asrt size
+    avio_wl32(out, MKTAG('a','s','r','t'));
+    avio_wb32(out, 0); // version + flags
+    avio_w8(out, 0); // QualityEntryCount
+    avio_wb32(out, 1); // SegmentRunEntryCount
+    avio_wb32(out, 1); // FirstSegment
+    avio_wb32(out, final ? (os->fragment_index - 1) : 0xffffffff); // FragmentsPerSegment
+    update_size(out, asrt_pos);
+    avio_w8(out, 1); // FragmentRunTableCount
+    afrt_pos = avio_tell(out);
+    avio_wb32(out, 0); // afrt size
+    avio_wl32(out, MKTAG('a','f','r','t'));
+    avio_wb32(out, 0); // version + flags
+    avio_wb32(out, 1000); // timescale
+    avio_w8(out, 0); // QualityEntryCount
+    avio_wb32(out, fragments); // FragmentRunEntryCount
+    for (i = start; i < os->nb_fragments; i++) {
+        avio_wb32(out, os->fragments[i]->n);
+        avio_wb64(out, os->fragments[i]->start_time);
+        avio_wb32(out, os->fragments[i]->duration);
+    }
+    update_size(out, afrt_pos);
+    update_size(out, 0);
+    avio_close(out);
+    rename(temp_filename, filename);
+    return 0;
+}
+
+static int init_file(AVFormatContext *s, OutputStream *os, int64_t start_ts)
+{
+    int ret, i;
+    ret = avio_open2(&os->out, os->temp_filename, AVIO_FLAG_WRITE,
+                     &s->interrupt_callback, NULL);
+    if (ret < 0)
+        return ret;
+    avio_wb32(os->out, 0);
+    avio_wl32(os->out, MKTAG('m','d','a','t'));
+    for (i = 0; i < os->nb_extra_packets; i++) {
+        AV_WB24(os->extra_packets[i] + 4, start_ts);
+        os->extra_packets[i][7] = (start_ts >> 24) & 0x7f;
+        avio_write(os->out, os->extra_packets[i], os->extra_packet_sizes[i]);
+    }
+    return 0;
+}
+
+static void close_file(OutputStream *os)
+{
+    int64_t pos = avio_tell(os->out);
+    avio_seek(os->out, 0, SEEK_SET);
+    avio_wb32(os->out, pos);
+    avio_flush(os->out);
+    avio_close(os->out);
+    os->out = NULL;
+}
+
+static int hds_write_header(AVFormatContext *s)
+{
+    HDSContext *c = s->priv_data;
+    int ret = 0, i;
+    AVOutputFormat *oformat;
+
+    mkdir(s->filename, 0777);
+
+    oformat = av_guess_format("flv", NULL, NULL);
+    if (!oformat) {
+        ret = AVERROR_MUXER_NOT_FOUND;
+        goto fail;
+    }
+
+    c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);
+    if (!c->streams) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[c->nb_streams];
+        AVFormatContext *ctx;
+        AVStream *st = s->streams[i];
+
+        if (!st->codec->bit_rate) {
+            av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
+            ret = AVERROR(EINVAL);
+            goto fail;
+        }
+        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+            if (os->has_video) {
+                c->nb_streams++;
+                os++;
+            }
+            os->has_video = 1;
+        } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
+            if (os->has_audio) {
+                c->nb_streams++;
+                os++;
+            }
+            os->has_audio = 1;
+        } else {
+            av_log(s, AV_LOG_ERROR, "Unsupported stream type in stream %d\n", i);
+            ret = AVERROR(EINVAL);
+            goto fail;
+        }
+        os->bitrate += s->streams[i]->codec->bit_rate;
+
+        if (!os->ctx) {
+            os->first_stream = i;
+            ctx = avformat_alloc_context();
+            if (!ctx) {
+                ret = AVERROR(ENOMEM);
+                goto fail;
+            }
+            os->ctx = ctx;
+            ctx->oformat = oformat;
+            ctx->interrupt_callback = s->interrupt_callback;
+
+            ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf),
+                                         AVIO_FLAG_WRITE, os,
+                                         NULL, hds_write, NULL);
+            if (!ctx->pb) {
+                ret = AVERROR(ENOMEM);
+                goto fail;
+            }
+        } else {
+            ctx = os->ctx;
+        }
+        s->streams[i]->id = c->nb_streams;
+
+        if (!(st = avformat_new_stream(ctx, NULL))) {
+            ret = AVERROR(ENOMEM);
+            goto fail;
+        }
+        avcodec_copy_context(st->codec, s->streams[i]->codec);
+        st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
+    }
+    if (c->streams[c->nb_streams].ctx)
+        c->nb_streams++;
+
+    for (i = 0; i < c->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        int j;
+        if ((ret = avformat_write_header(os->ctx, NULL)) < 0) {
+             goto fail;
+        }
+        os->ctx_inited = 1;
+        avio_flush(os->ctx->pb);
+        for (j = 0; j < os->ctx->nb_streams; j++)
+            s->streams[os->first_stream + j]->time_base = os->ctx->streams[j]->time_base;
+
+        snprintf(os->temp_filename, sizeof(os->temp_filename),
+                 "%s/stream%d_temp", s->filename, i);
+        init_file(s, os, 0);
+
+        if (!os->has_video && c->min_frag_duration <= 0) {
+            av_log(s, AV_LOG_WARNING,
+                   "No video stream in output stream %d and no min frag duration set\n", i);
+            ret = AVERROR(EINVAL);
+        }
+        os->fragment_index = 1;
+        write_abst(s, os, 0);
+    }
+    ret = write_manifest(s, 0);
+
+fail:
+    if (ret)
+        hds_free(s);
+    return ret;
+}
+
+static int add_fragment(OutputStream *os, const char *file,
+                        int64_t start_time, int64_t duration)
+{
+    Fragment *frag;
+    if (duration == 0)
+        duration = 1;
+    if (os->nb_fragments >= os->fragments_size) {
+        int ret;
+        os->fragments_size = (os->fragments_size + 1) * 2;
+        if ((ret = av_reallocp_array(&os->fragments, os->fragments_size,
+                                     sizeof(*os->fragments))) < 0) {
+            os->fragments_size = 0;
+            os->nb_fragments   = 0;
+            return ret;
+        }
+    }
+    frag = av_mallocz(sizeof(*frag));
+    if (!frag)
+        return AVERROR(ENOMEM);
+    av_strlcpy(frag->file, file, sizeof(frag->file));
+    frag->start_time = start_time;
+    frag->duration   = duration;
+    frag->n          = os->fragment_index;
+    os->fragments[os->nb_fragments++] = frag;
+    os->fragment_index++;
+    return 0;
+}
+
+static int hds_flush(AVFormatContext *s, OutputStream *os, int final,
+                     int64_t end_ts)
+{
+    HDSContext *c = s->priv_data;
+    int i, ret = 0;
+    char target_filename[1024];
+    int index = s->streams[os->first_stream]->id;
+
+    if (!os->packets_written)
+        return 0;
+
+    avio_flush(os->ctx->pb);
+    os->packets_written = 0;
+    close_file(os);
+
+    snprintf(target_filename, sizeof(target_filename),
+             "%s/stream%dSeg1-Frag%d", s->filename, index, os->fragment_index);
+    rename(os->temp_filename, target_filename);
+    add_fragment(os, target_filename, os->frag_start_ts, end_ts - os->frag_start_ts);
+
+    if (!final) {
+        ret = init_file(s, os, end_ts);
+        if (ret < 0)
+            return ret;
+    }
+
+    if (c->window_size || (final && c->remove_at_exit)) {
+        int remove = os->nb_fragments - c->window_size - c->extra_window_size;
+        if (final && c->remove_at_exit)
+            remove = os->nb_fragments;
+        if (remove > 0) {
+            for (i = 0; i < remove; i++) {
+                unlink(os->fragments[i]->file);
+                av_free(os->fragments[i]);
+            }
+            os->nb_fragments -= remove;
+            memmove(os->fragments, os->fragments + remove,
+                    os->nb_fragments * sizeof(*os->fragments));
+        }
+    }
+
+    if (ret >= 0)
+        ret = write_abst(s, os, final);
+    return ret;
+}
+
+static int hds_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    HDSContext *c = s->priv_data;
+    AVStream *st = s->streams[pkt->stream_index];
+    OutputStream *os = &c->streams[s->streams[pkt->stream_index]->id];
+    int64_t end_dts = (os->fragment_index) * c->min_frag_duration;
+    int ret;
+
+    if (st->first_dts == AV_NOPTS_VALUE)
+        st->first_dts = pkt->dts;
+
+    if ((!os->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
+        av_compare_ts(pkt->dts - st->first_dts, st->time_base,
+                      end_dts, AV_TIME_BASE_Q) >= 0 &&
+        pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
+
+        if ((ret = hds_flush(s, os, 0, pkt->dts)) < 0)
+            return ret;
+    }
+
+    // Note, these fragment start timestamps, that represent a whole
+    // OutputStream, assume all streams in it have the same time base.
+    if (!os->packets_written)
+        os->frag_start_ts = pkt->dts;
+    os->last_ts = pkt->dts;
+
+    os->packets_written++;
+    return ff_write_chained(os->ctx, pkt->stream_index - os->first_stream, pkt, s);
+}
+
+static int hds_write_trailer(AVFormatContext *s)
+{
+    HDSContext *c = s->priv_data;
+    int i;
+
+    for (i = 0; i < c->nb_streams; i++)
+        hds_flush(s, &c->streams[i], 1, c->streams[i].last_ts);
+    write_manifest(s, 1);
+
+    if (c->remove_at_exit) {
+        char filename[1024];
+        snprintf(filename, sizeof(filename), "%s/index.f4m", s->filename);
+        unlink(filename);
+        for (i = 0; i < c->nb_streams; i++) {
+            snprintf(filename, sizeof(filename), "%s/stream%d.abst", s->filename, i);
+            unlink(filename);
+        }
+        rmdir(s->filename);
+    }
+
+    hds_free(s);
+    return 0;
+}
+
+#define OFFSET(x) offsetof(HDSContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
+    { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
+    { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 10000000 }, 0, INT_MAX, E },
+    { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
+    { NULL },
+};
+
+static const AVClass hds_class = {
+    .class_name = "HDS muxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_hds_muxer = {
+    .name           = "hds",
+    .long_name      = NULL_IF_CONFIG_SMALL("HDS Muxer"),
+    .priv_data_size = sizeof(HDSContext),
+    .audio_codec    = AV_CODEC_ID_AAC,
+    .video_codec    = AV_CODEC_ID_H264,
+    .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
+    .write_header   = hds_write_header,
+    .write_packet   = hds_write_packet,
+    .write_trailer  = hds_write_trailer,
+    .priv_class     = &hds_class,
+};