[FFmpeg-devel] [PATCH 2/7] avformat/hlsenc: make the code easier to read
Nicolas Martyanoff
khaelin at gmail.com
Fri Jul 18 10:57:42 CEST 2014
Before adding new features, I read the code and cleaned it. The main issue was
abstruse identifier names.
The behaviour of the muxer is *not* modified, by this patch, this is only
cosmetic. If this is not the case, it is a mistake.
---
libavformat/hlsenc.c | 360 ++++++++++++++++++++++++++++++---------------------
1 file changed, 213 insertions(+), 147 deletions(-)
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index 388a23a..30b320f 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -31,236 +31,294 @@
#include "avformat.h"
#include "internal.h"
-typedef struct ListEntry {
- char name[1024];
- double duration;
- struct ListEntry *next;
-} ListEntry;
+typedef struct HLSSegment {
+ char filename[1024];
+ double duration; /* in seconds */
+
+ struct HLSSegment *next;
+} HLSSegment;
typedef struct HLSContext {
const AVClass *class; // Class for private options.
+
unsigned number;
int64_t sequence;
int64_t start_sequence;
+
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.
+ AVFormatContext *ctx;
+
+ float target_duration;
+ int max_nb_segments;
+ int wrap;
+
int64_t recording_time;
int has_video;
int64_t start_pts;
int64_t end_pts;
double duration; // last segment duration computed so far, in seconds
int nb_entries;
- ListEntry *list;
- ListEntry *end_list;
- char *basename;
+
+ HLSSegment *segments;
+ HLSSegment *last_segment;
+
+ char *media_filename;
char *baseurl;
+
AVIOContext *pb;
} HLSContext;
-static int hls_mux_init(AVFormatContext *s)
+static int hls_mux_init(AVFormatContext *ctx)
{
- HLSContext *hls = s->priv_data;
- AVFormatContext *oc;
+ HLSContext *hls;
int i;
- hls->avf = oc = avformat_alloc_context();
- if (!oc)
+ hls = ctx->priv_data;
+
+ hls->ctx = avformat_alloc_context();
+ if (!hls->ctx)
return AVERROR(ENOMEM);
- oc->oformat = hls->oformat;
- oc->interrupt_callback = s->interrupt_callback;
- av_dict_copy(&oc->metadata, s->metadata, 0);
+ hls->ctx->oformat = hls->oformat;
+ hls->ctx->interrupt_callback = ctx->interrupt_callback;
+ av_dict_copy(&hls->ctx->metadata, ctx->metadata, 0);
- for (i = 0; i < s->nb_streams; i++) {
- AVStream *st;
- if (!(st = avformat_new_stream(oc, NULL)))
+ for (i = 0; i < ctx->nb_streams; i++) {
+ AVStream *stream;
+
+ stream = avformat_new_stream(hls->ctx, NULL);
+ if (!stream)
return AVERROR(ENOMEM);
- avcodec_copy_context(st->codec, s->streams[i]->codec);
- st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
+
+ avcodec_copy_context(stream->codec, ctx->streams[i]->codec);
+ stream->sample_aspect_ratio = ctx->streams[i]->sample_aspect_ratio;
}
return 0;
}
-static int append_entry(HLSContext *hls, double duration)
+static int hls_append_segment(HLSContext *hls, double duration)
{
- ListEntry *en = av_malloc(sizeof(*en));
+ const char *basename;
+ HLSSegment *segment;
- if (!en)
+ /* Create a new segment and append it to the segment list */
+
+ segment = av_malloc(sizeof(*segment));
+ if (!segment)
return AVERROR(ENOMEM);
- av_strlcpy(en->name, av_basename(hls->avf->filename), sizeof(en->name));
+ basename = av_basename(hls->ctx->filename);
+ av_strlcpy(segment->filename, basename, sizeof(segment->filename));
- en->duration = duration;
- en->next = NULL;
+ segment->duration = duration;
+ segment->next = NULL;
- if (!hls->list)
- hls->list = en;
- else
- hls->end_list->next = en;
+ if (!hls->segments) {
+ hls->segments = segment;
+ } else {
+ hls->last_segment->next = segment;
+ }
- hls->end_list = en;
+ hls->last_segment = segment;
- if (hls->size && hls->nb_entries >= hls->size) {
- en = hls->list;
- hls->list = en->next;
- av_free(en);
- } else
+ if (hls->max_nb_segments > 0 && hls->nb_entries >= hls->max_nb_segments) {
+ segment = hls->segments;
+ hls->segments = segment->next;
+ av_free(segment);
+ } else {
hls->nb_entries++;
+ }
hls->sequence++;
return 0;
}
-static void free_entries(HLSContext *hls)
+static void hls_free_segments(HLSContext *hls)
{
- ListEntry *p = hls->list, *en;
+ HLSSegment *segment;
- while(p) {
- en = p;
- p = p->next;
- av_free(en);
+ segment = hls->segments;
+
+ while (segment) {
+ HLSSegment *next;
+
+ next = segment->next;
+ av_free(segment);
+ segment = next;
}
}
-static int hls_window(AVFormatContext *s, int last)
+static int hls_generate_playlist(AVFormatContext *ctx, int last)
{
- HLSContext *hls = s->priv_data;
- ListEntry *en;
- int target_duration = 0;
- int ret = 0;
- int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);
-
- if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
- &s->interrupt_callback, NULL)) < 0)
- goto fail;
+ HLSContext *hls;
+ HLSSegment *segment;
+ int target_duration;
+ int64_t sequence;
+ int ret;
+
+ hls = ctx->priv_data;
+ target_duration = 0;
+ ret = 0;
+
+ ret = avio_open2(&hls->pb, ctx->filename, AVIO_FLAG_WRITE,
+ &ctx->interrupt_callback, NULL);
+ if (ret < 0)
+ return ret;
- for (en = hls->list; en; en = en->next) {
- if (target_duration < en->duration)
- target_duration = ceil(en->duration);
+ for (segment = hls->segments; segment; segment = segment->next) {
+ if (segment->duration > target_duration)
+ target_duration = ceil(segment->duration);
}
avio_printf(hls->pb, "#EXTM3U\n");
avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", target_duration);
- avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
- av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
- sequence);
+ sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);
+ avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
- for (en = hls->list; en; en = en->next) {
- avio_printf(hls->pb, "#EXTINF:%f,\n", en->duration);
- if (hls->baseurl)
- avio_printf(hls->pb, "%s", hls->baseurl);
- avio_printf(hls->pb, "%s\n", en->name);
+ for (segment = hls->segments; segment; segment = segment->next) {
+ avio_printf(hls->pb, "#EXTINF:%f,\n", segment->duration);
+ avio_printf(hls->pb, "%s%s\n",
+ (hls->baseurl ? hls->baseurl : ""), segment->filename);
}
if (last)
avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
-fail:
avio_closep(&hls->pb);
- return ret;
+ return 0;
}
-static int hls_start(AVFormatContext *s)
+static int hls_create_file(AVFormatContext *ctx)
{
- HLSContext *c = s->priv_data;
- AVFormatContext *oc = c->avf;
- int err = 0;
+ HLSContext *hls;
+ int file_idx;
+ int ret;
+
+ hls = ctx->priv_data;
- if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
- c->basename, c->wrap ? c->sequence % c->wrap : c->sequence) < 0) {
- av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->basename);
+ ret = 0;
+
+ if (hls->wrap) {
+ file_idx = hls->sequence % hls->wrap;
+ } else {
+ file_idx = hls->sequence;
+ }
+
+ if (av_get_frame_filename(hls->ctx->filename, sizeof(hls->ctx->filename),
+ hls->media_filename, file_idx) < 0) {
+ av_log(hls->ctx, AV_LOG_ERROR,
+ "Invalid segment filename template '%s'\n", hls->media_filename);
return AVERROR(EINVAL);
}
- c->number++;
+ hls->number++;
- if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
- &s->interrupt_callback, NULL)) < 0)
- return err;
+ ret = avio_open2(&hls->ctx->pb, hls->ctx->filename, AVIO_FLAG_WRITE,
+ &ctx->interrupt_callback, NULL);
+ if (ret < 0)
+ return ret;
- if (oc->oformat->priv_class && oc->priv_data)
- av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
+ if (hls->ctx->oformat->priv_class && hls->ctx->priv_data)
+ av_opt_set(hls->ctx->priv_data, "mpegts_flags", "resend_headers", 0);
return 0;
}
-static int hls_write_header(AVFormatContext *s)
+static int hls_write_header(AVFormatContext *ctx)
{
- HLSContext *hls = s->priv_data;
+ HLSContext *hls;
int ret, i;
- char *p;
- const char *pattern = "%d.ts";
- int basename_size = strlen(s->filename) + strlen(pattern) + 1;
+ char *dot;
+ size_t basename_size;
+ char filename[1024];
+
+ hls = ctx->priv_data;
hls->sequence = hls->start_sequence;
- hls->recording_time = hls->time * AV_TIME_BASE;
+ hls->recording_time = hls->target_duration * AV_TIME_BASE;
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;
+ /* Findout if the input file contains a video stream */
+ for (i = 0; i < ctx->nb_streams; i++) {
+ AVStream *stream;
+
+ stream = ctx->streams[i];
+ hls->has_video += stream->codec->codec_type == AVMEDIA_TYPE_VIDEO;
+ }
- if (hls->has_video > 1)
- av_log(s, AV_LOG_WARNING,
+ if (hls->has_video > 1) {
+ av_log(ctx, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
+ }
+ /* HLS demands that media files use the MPEG-TS container */
hls->oformat = av_guess_format("mpegts", NULL, NULL);
-
if (!hls->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
- hls->basename = av_malloc(basename_size);
+ /* Generate the basename of all generated media files */
+ av_strlcpy(filename, ctx->filename, sizeof(filename));
+ dot = strrchr(filename, '.');
+ if (dot)
+ *dot = '\0';
- if (!hls->basename) {
+ basename_size = sizeof(filename);
+ hls->media_filename = av_malloc(basename_size);
+ if (!hls->media_filename) {
ret = AVERROR(ENOMEM);
goto fail;
}
- strcpy(hls->basename, s->filename);
-
- p = strrchr(hls->basename, '.');
-
- if (p)
- *p = '\0';
+ av_strlcpy(hls->media_filename, filename, basename_size);
+ av_strlcat(hls->media_filename, "%d.ts", basename_size);
- av_strlcat(hls->basename, pattern, basename_size);
-
- if ((ret = hls_mux_init(s)) < 0)
+ /* Initialize the muxer and create the first file */
+ ret = hls_mux_init(ctx);
+ if (ret < 0)
goto fail;
- if ((ret = hls_start(s)) < 0)
+ ret = hls_create_file(ctx);
+ if (ret < 0)
goto fail;
- if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
+ ret = avformat_write_header(hls->ctx, NULL);
+ if (ret < 0)
return ret;
+ return 0;
fail:
if (ret) {
- av_free(hls->basename);
- if (hls->avf)
- avformat_free_context(hls->avf);
+ av_free(hls->media_filename);
+ if (hls->ctx)
+ avformat_free_context(hls->ctx);
}
+
return ret;
}
-static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
+static int hls_write_packet(AVFormatContext *ctx, 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 is_ref_pkt = 1;
- int ret, can_split = 1;
+ HLSContext *hls;
+ AVStream *stream;
+ int64_t end_pts;
+ int64_t pkt_ts;
+ int is_ref_pkt;
+ int ret, can_split;
+
+ hls = ctx->priv_data;
+ stream = ctx->streams[pkt->stream_index];
+
+ is_ref_pkt = 1;
+ can_split = 1;
+
+ end_pts = hls->recording_time * hls->number;
if (hls->start_pts == AV_NOPTS_VALUE) {
hls->start_pts = pkt->pts;
@@ -268,58 +326,66 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
}
if (hls->has_video) {
- can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
- pkt->flags & AV_PKT_FLAG_KEY;
- is_ref_pkt = st->codec->codec_type == AVMEDIA_TYPE_VIDEO;
+ can_split = (pkt->flags & AV_PKT_FLAG_KEY)
+ && (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO);
+ is_ref_pkt = (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO);
}
+
if (pkt->pts == AV_NOPTS_VALUE)
is_ref_pkt = can_split = 0;
- if (is_ref_pkt)
- hls->duration = (double)(pkt->pts - hls->end_pts)
- * st->time_base.num / st->time_base.den;
+ if (is_ref_pkt) {
+ double pts_diff;
+
+ pts_diff = pkt->pts - hls->end_pts;
- if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
+ hls->duration = pts_diff * stream->time_base.num
+ / stream->time_base.den;
+ }
+
+ pkt_ts = pkt->pts - hls->start_pts;
+
+ if (can_split && av_compare_ts(pkt_ts, stream->time_base,
end_pts, AV_TIME_BASE_Q) >= 0) {
- ret = append_entry(hls, hls->duration);
+ ret = hls_append_segment(hls, hls->duration);
if (ret)
return ret;
hls->end_pts = pkt->pts;
hls->duration = 0;
- av_write_frame(oc, NULL); /* Flush any buffered data */
- avio_close(oc->pb);
-
- ret = hls_start(s);
+ /* Flush any buffered data and close the current file */
+ av_write_frame(hls->ctx, NULL);
+ avio_close(hls->ctx->pb);
+ /* Open the next file */
+ ret = hls_create_file(ctx);
if (ret)
return ret;
- oc = hls->avf;
-
- if ((ret = hls_window(s, 0)) < 0)
+ ret = hls_generate_playlist(ctx, 0);
+ if (ret < 0)
return ret;
}
- ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
-
+ ret = ff_write_chained(hls->ctx, pkt->stream_index, pkt, ctx);
return ret;
}
-static int hls_write_trailer(struct AVFormatContext *s)
+static int hls_write_trailer(struct AVFormatContext *ctx)
{
- HLSContext *hls = s->priv_data;
- AVFormatContext *oc = hls->avf;
+ HLSContext *hls;
+
+ hls = ctx->priv_data;
- av_write_trailer(oc);
- avio_closep(&oc->pb);
- avformat_free_context(oc);
- av_free(hls->basename);
- append_entry(hls, hls->duration);
- hls_window(s, 1);
+ av_write_trailer(hls->ctx);
+ avio_closep(&hls->ctx->pb);
+ avformat_free_context(hls->ctx);
+ av_free(hls->media_filename);
+ hls_append_segment(hls, hls->duration);
+ hls_generate_playlist(ctx, 1);
- free_entries(hls);
+ hls_free_segments(hls);
avio_close(hls->pb);
return 0;
}
@@ -328,8 +394,8 @@ static int hls_write_trailer(struct AVFormatContext *s)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{"start_number", "set first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E},
- {"hls_time", "set segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
- {"hls_list_size", "set maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
+ {"hls_time", "set segment length in seconds", OFFSET(target_duration), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
+ {"hls_list_size", "set maximum number of playlist entries", OFFSET(max_nb_segments), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
{"hls_wrap", "set number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
{"hls_base_url", "url to prepend to each playlist entry", OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
{ NULL },
--
1.8.5.5
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