lavf: add a flag to enable/disable automatic bitstream filtering

This is mostly useful for muxers that wrap other muxers, such as dashenc
and segment. The actual duplicated bitstream filtering is largely harmless,
but delaying the header can cause problems when the muxer intended the header
to be written to a separate file.
This commit is contained in:
Rodger Combs 2016-04-07 02:59:39 -05:00
parent 5e1bf9d8c0
commit 1f6d7eb470
No known key found for this signature in database
GPG Key ID: E3E54DCDCD3CB843
3 changed files with 7 additions and 2 deletions

View File

@ -1449,6 +1449,7 @@ typedef struct AVFormatContext {
#define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
#define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
#define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
#define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Wait for packet data before writing a header, and add bitstream filters as requested by the muxer
/**
* Maximum size of the data read from input for determining

View File

@ -500,7 +500,7 @@ int avformat_write_header(AVFormatContext *s, AVDictionary **options)
if ((ret = init_muxer(s, options)) < 0)
return ret;
if (!s->oformat->check_bitstream) {
if (!(s->oformat->check_bitstream && s->flags & AVFMT_FLAG_AUTO_BSF)) {
ret = write_header_internal(s);
if (ret < 0)
goto fail;
@ -830,6 +830,9 @@ static int do_packet_auto_bsf(AVFormatContext *s, AVPacket *pkt) {
AVStream *st = s->streams[pkt->stream_index];
int i, ret;
if (!(s->flags & AVFMT_FLAG_AUTO_BSF))
return 1;
if (s->oformat->check_bitstream) {
if (!st->internal->bitstream_checked) {
if ((ret = s->oformat->check_bitstream(s, pkt)) < 0)

View File

@ -39,7 +39,7 @@ static const AVOption avformat_options[] = {
{"probesize", "set probing size", OFFSET(probesize), AV_OPT_TYPE_INT64, {.i64 = 5000000 }, 32, INT64_MAX, D},
{"formatprobesize", "number of bytes to probe file format", OFFSET(format_probesize), AV_OPT_TYPE_INT, {.i64 = PROBE_BUF_MAX}, 0, INT_MAX-1, D},
{"packetsize", "set packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, INT_MAX, E},
{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, D|E, "fflags"},
{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_FLUSH_PACKETS | AVFMT_FLAG_AUTO_BSF }, INT_MIN, INT_MAX, D|E, "fflags"},
{"flush_packets", "reduce the latency by flushing out packets immediately", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, E, "fflags"},
{"ignidx", "ignore index", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_IGNIDX }, INT_MIN, INT_MAX, D, "fflags"},
{"genpts", "generate pts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_GENPTS }, INT_MIN, INT_MAX, D, "fflags"},
@ -55,6 +55,7 @@ static const AVOption avformat_options[] = {
{"seek2any", "allow seeking to non-keyframes on demuxer level when supported", OFFSET(seek2any), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, D},
{"bitexact", "do not write random/volatile data", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_BITEXACT }, 0, 0, E, "fflags" },
{"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E, "fflags" },
{"autobsf", "add needed bsfs automatically (delays header until each stream's first packet is written)", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, "fflags" },
{"analyzeduration", "specify how many microseconds are analyzed to probe the input", OFFSET(max_analyze_duration), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},
{"cryptokey", "decryption key", OFFSET(key), AV_OPT_TYPE_BINARY, {.dbl = 0}, 0, 0, D},
{"indexmem", "max memory used for timestamp index (per stream)", OFFSET(max_index_size), AV_OPT_TYPE_INT, {.i64 = 1<<20 }, 0, INT_MAX, D},