[FFmpeg-devel] [PATCH 1/8] libavformat/dashenc: use avio_dynbuf instead of packet_write callback
Peter Große
pegro at friiks.de
Sat Jan 21 16:39:02 EET 2017
The dash_write function drops data, if no IOContext is initialized.
This might happen when a subordinate muxer calls avio_flush().
Using a dynamic buffer fixes that.
Signed-off-by: Peter Große <pegro at friiks.de>
---
libavformat/dashenc.c | 86 +++++++++++++++++++++++++++++++--------------------
1 file changed, 53 insertions(+), 33 deletions(-)
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 534fa75..d0a2ab5 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -62,11 +62,10 @@ typedef struct Segment {
typedef struct OutputStream {
AVFormatContext *ctx;
int ctx_inited;
- uint8_t iobuf[32768];
AVIOContext *out;
int packets_written;
char initfile[1024];
- int64_t init_start_pos;
+ int64_t init_start_pos, pos;
int init_range_length;
int nb_segments, segments_size, segment_index;
Segment **segments;
@@ -100,14 +99,6 @@ typedef struct DASHContext {
int ambiguous_frame_rate;
} DASHContext;
-static int dash_write(void *opaque, uint8_t *buf, int buf_size)
-{
- OutputStream *os = opaque;
- if (os->out)
- avio_write(os->out, buf, buf_size);
- return buf_size;
-}
-
// RFC 6381
static void set_codec_str(AVFormatContext *s, AVCodecParameters *par,
char *str, int size)
@@ -174,6 +165,29 @@ static void set_codec_str(AVFormatContext *s, AVCodecParameters *par,
}
}
+static int flush_dynbuf(OutputStream *os, int *range_length)
+{
+ uint8_t *buffer;
+ int ret;
+
+ if(!os->ctx->pb) {
+ return AVERROR(EINVAL);
+ }
+
+ // flush everything
+ av_write_frame(os->ctx, NULL);
+ avio_flush(os->ctx->pb);
+
+ // write to output
+ *range_length = avio_close_dyn_buf(os->ctx->pb, &buffer);
+ avio_write(os->out, buffer, *range_length);
+ av_free(buffer);
+
+ // re-open buffer
+ ret = avio_open_dyn_buf(&os->ctx->pb);
+ return ret;
+}
+
static void dash_free(AVFormatContext *s)
{
DASHContext *c = s->priv_data;
@@ -185,7 +199,7 @@ static void dash_free(AVFormatContext *s)
if (os->ctx && os->ctx_inited)
av_write_trailer(os->ctx);
if (os->ctx && os->ctx->pb)
- av_free(os->ctx->pb);
+ ffio_free_dyn_buf(&os->ctx->pb);
ff_format_io_close(s, &os->out);
if (os->ctx)
avformat_free_context(os->ctx);
@@ -624,9 +638,10 @@ static int dash_init(AVFormatContext *s)
ctx->avoid_negative_ts = s->avoid_negative_ts;
ctx->flags = s->flags;
- ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, dash_write, NULL);
- if (!ctx->pb)
- return AVERROR(ENOMEM);
+ ret = avio_open_dyn_buf(&ctx->pb);
+ if (ret < 0)
+ return ret;
+ ctx->pb->seekable = 0;
if (c->single_file) {
if (c->single_file_name)
@@ -646,7 +661,6 @@ static int dash_init(AVFormatContext *s)
if ((ret = avformat_init_output(ctx, &opts)) < 0)
return ret;
os->ctx_inited = 1;
- avio_flush(ctx->pb);
av_dict_free(&opts);
av_log(s, AV_LOG_VERBOSE, "Representation %d init segment will be written to: %s\n", i, filename);
@@ -688,13 +702,24 @@ static int dash_init(AVFormatContext *s)
static int dash_write_header(AVFormatContext *s)
{
DASHContext *c = s->priv_data;
- int i, ret;
+ int i, ret, range_length;
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
if ((ret = avformat_write_header(os->ctx, NULL)) < 0) {
dash_free(s);
return ret;
}
+
+ if ((ret = flush_dynbuf(os, &range_length)) < 0) {
+ dash_free(s);
+ return ret;
+ }
+
+ if (!c->single_file) {
+ ff_format_io_close(s, &os->out);
+ }
+
+ os->pos = os->init_range_length = range_length;
}
ret = write_manifest(s, 0);
if (!ret)
@@ -803,7 +828,6 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
char filename[1024] = "", full_path[1024], temp_path[1024];
- int64_t start_pos;
int range_length, index_length = 0;
if (!os->packets_written)
@@ -821,15 +845,6 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
continue;
}
- if (!os->init_range_length) {
- av_write_frame(os->ctx, NULL);
- os->init_range_length = avio_tell(os->ctx->pb);
- if (!c->single_file)
- ff_format_io_close(s, &os->out);
- }
-
- start_pos = avio_tell(os->ctx->pb);
-
if (!c->single_file) {
dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_pts);
snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename);
@@ -837,26 +852,31 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
ret = s->io_open(s, &os->out, temp_path, AVIO_FLAG_WRITE, NULL);
if (ret < 0)
break;
- write_styp(os->ctx->pb);
} else {
snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, os->initfile);
}
- av_write_frame(os->ctx, NULL);
- avio_flush(os->ctx->pb);
- os->packets_written = 0;
+ ret = flush_dynbuf(os, &range_length);
+ if (ret < 0)
+ break;
- range_length = avio_tell(os->ctx->pb) - start_pos;
if (c->single_file) {
- find_index_range(s, full_path, start_pos, &index_length);
+ find_index_range(s, full_path, os->pos, &index_length);
} else {
ff_format_io_close(s, &os->out);
ret = avpriv_io_move(temp_path, full_path);
if (ret < 0)
break;
}
- add_segment(os, filename, os->start_pts, os->max_pts - os->start_pts, start_pos, range_length, index_length);
+ add_segment(os, filename, os->start_pts, os->max_pts - os->start_pts, os->pos, range_length, index_length);
av_log(s, AV_LOG_VERBOSE, "Representation %d media segment %d written to: %s\n", i, os->segment_index, full_path);
+
+ // set new position
+ os->packets_written = 0;
+ os->pos += range_length;
+
+ // write chunk header
+ write_styp(os->ctx->pb);
}
if (c->window_size || (final && c->remove_at_exit)) {
--
2.10.2
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