[FFmpeg-devel] [PATCH] lavf/tee: add support for bitstream filtering
Nicolas George
nicolas.george at normalesup.org
Fri Aug 16 12:40:48 CEST 2013
Le sextidi 26 thermidor, an CCXXI, Stefano Sabatini a écrit :
> This allows to apply different bitstream filters to different outputs,
> with no need to trancode.
>
> TODO: bump minor
> ---
> doc/muxers.texi | 19 ++++-
> libavformat/tee.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++-----
> 2 files changed, 208 insertions(+), 19 deletions(-)
>
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index d204188..0f4db3c 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -852,11 +852,28 @@ leading or trailing spaces or any special character, it must be
> escaped (see the ``Quoting and escaping'' section in the ffmpeg-utils
> manual).
>
> -Options can be specified for each slave by prepending them as a list of
> +Muxer options can be specified for each slave by prepending them as a list of
> @var{key}=@var{value} pairs separated by ':', between square brackets. If
> the options values contain a special character or the ':' separator, they
> must be escaped; note that this is a second level escaping.
>
> +The following special options are also recognized:
> + at table @option
> + at item f
> +Specify the format name. Useful if it cannot be guessed from the
> +output name suffix.
> +
> + at item bsfs[/@var{spec}]
> +Specify a list of bitstream filters to apply to the specified
> +output. It is possible to specify to which streams a given bitstream
> +filter applies, by appending a stream specifier to the option
> +separated by @code{/} . If the stream specifier is not specified, the
> +bistream filters will be applied to all streams in the output.
> +
> +Several bitstream filters can be specified, separated by ",".
> + at end example
> + at end table
> +
> Example: encode something and both archive it in a WebM file and stream it
> as MPEG-TS over UDP (the streams need to be explicitly mapped):
>
> diff --git a/libavformat/tee.c b/libavformat/tee.c
> index 7b8b371..e959731 100644
> --- a/libavformat/tee.c
> +++ b/libavformat/tee.c
> @@ -27,10 +27,15 @@
>
> #define MAX_SLAVES 16
>
> +typedef struct {
> + AVFormatContext *avf;
> + AVBitStreamFilterContext **bsfs; ///< bitstream filters per stream
> +} TeeSlave;
> +
> typedef struct TeeContext {
> const AVClass *class;
> unsigned nb_slaves;
> - AVFormatContext *slaves[MAX_SLAVES];
> + TeeSlave slaves[MAX_SLAVES];
> } TeeContext;
>
> static const char *const slave_delim = "|";
> @@ -82,7 +87,53 @@ fail:
> return ret;
> }
>
> -static int open_slave(AVFormatContext *avf, char *slave, AVFormatContext **ravf)
> +/**
> + * Parse list of bitstream filters and add them to the list of filters
> + * pointed to by bsfs.
> + *
> + * The list must be specified in the form:
> + * BSFS ::= BSF[,BSFS]
> + */
> +static int parse_bsfs(void *log_ctx, const char *bsfs_spec,
> + AVBitStreamFilterContext **bsfs)
> +{
> + char *bsf_name, *buf, *saveptr;
> + int ret;
> +
> + if (!(buf = av_strdup(bsfs_spec)))
> + return AVERROR(ENOMEM);
> +
> + while (bsf_name = av_strtok(buf, ",", &saveptr)) {
> + AVBitStreamFilterContext *bsf = av_bitstream_filter_init(bsf_name);
> +
> + if (!bsf) {
> + av_log(log_ctx, AV_LOG_ERROR,
> + "Cannot initialize bitstream filter with name '%s', "
> + "unknown filter or internal error happened\n",
> + bsf_name);
> + ret = AVERROR_UNKNOWN;
> + goto end;
> + }
> +
> + /* append bsf context to the list of bsf contexts */
> + if (!*bsfs) {
> + *bsfs = bsf;
> + } else {
> + AVBitStreamFilterContext *bsf1 = *bsfs;
> + while (bsf1->next)
> + bsf1 = bsf1->next;
> + bsf1->next = bsf;
> + }
Simpler:
*bsfs = bsf;
bsfs = &bsf->next;
> +
> + buf = NULL;
> + }
> +
> +end:
> + av_free(buf);
> + return ret;
> +}
> +
> +static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
> {
> int i, ret;
> AVDictionary *options = NULL;
> @@ -102,14 +153,13 @@ static int open_slave(AVFormatContext *avf, char *slave, AVFormatContext **ravf)
>
> ret = avformat_alloc_output_context2(&avf2, NULL, format, filename);
> if (ret < 0)
> - goto fail;
> - av_free(format);
> + goto end;
>
> for (i = 0; i < avf->nb_streams; i++) {
> st = avf->streams[i];
> if (!(st2 = avformat_new_stream(avf2, NULL))) {
> ret = AVERROR(ENOMEM);
> - goto fail;
> + goto end;
> }
> st2->id = st->id;
> st2->r_frame_rate = st->r_frame_rate;
> @@ -122,34 +172,79 @@ static int open_slave(AVFormatContext *avf, char *slave, AVFormatContext **ravf)
> st2->avg_frame_rate = st->avg_frame_rate;
> av_dict_copy(&st2->metadata, st->metadata, 0);
> if ((ret = avcodec_copy_context(st2->codec, st->codec)) < 0)
> - goto fail;
> + goto end;
> }
>
> if (!(avf2->oformat->flags & AVFMT_NOFILE)) {
> if ((ret = avio_open(&avf2->pb, filename, AVIO_FLAG_WRITE)) < 0) {
> av_log(avf, AV_LOG_ERROR, "Slave '%s': error opening: %s\n",
> slave, av_err2str(ret));
> - goto fail;
> + goto end;
> }
> }
>
> if ((ret = avformat_write_header(avf2, &options)) < 0) {
> av_log(avf, AV_LOG_ERROR, "Slave '%s': error writing header: %s\n",
> slave, av_err2str(ret));
> - goto fail;
> + goto end;
> + }
> +
> + tee_slave->avf = avf2;
> + tee_slave->bsfs = av_calloc(avf2->nb_streams, sizeof(TeeSlave));
> + if (!tee_slave->bsfs) {
> + ret = AVERROR(ENOMEM);
> + goto end;
> + }
> + memset(tee_slave->bsfs, 0, avf2->nb_streams * sizeof(TeeSlave));
Unnecessary, calloc already does it.
> +
> + entry = NULL;
> + while (entry = av_dict_get(options, "bsfs", NULL, AV_DICT_IGNORE_SUFFIX)) {
> + const char *spec = entry->key + strlen("bsfs");
> + if (*spec)
> + spec++; /* consume separator */
Possibly: check that this is indeed the separator.
> +
> + for (i = 0; i < avf2->nb_streams; i++) {
> + ret = avformat_match_stream_specifier(avf2, avf2->streams[i], spec);
> + if (ret < 0) {
> + av_log(avf, AV_LOG_ERROR,
> + "Invalid stream specifier '%s' in bsfs option '%s' for slave "
> + "output '%s'\n", spec, entry->key, filename);
> + goto end;
> + }
> +
> + if (ret > 0) {
> + av_log(avf, AV_LOG_DEBUG, "spec:%s bsfs:%s matches stream %d of slave "
> + "output '%s'\n", spec, entry->value, i, filename);
> + if (tee_slave->bsfs[i]) {
> + av_log(avf, AV_LOG_WARNING,
> + "Duplicate bsfs specification associated to stream %d of slave "
> + "output '%s', filters will be ignored\n", i, filename);
> + continue;
> + }
> + ret = parse_bsfs(avf, entry->value, &tee_slave->bsfs[i]);
> + if (ret < 0) {
> + av_log(avf, AV_LOG_ERROR,
> + "Error parsing bitstream filter sequence '%s' associated to "
> + "stream %d of slave output '%s'\n", entry->value, i, filename);
> + goto end;
> + }
> + }
> + }
> +
> + entry->value = NULL;
> + av_dict_set(&options, entry->key, NULL, 0);
I suspect entry->value is leaking now.
> }
> +
> if (options) {
> entry = NULL;
> while ((entry = av_dict_get(options, "", entry, AV_DICT_IGNORE_SUFFIX)))
> av_log(avf2, AV_LOG_ERROR, "Unknown option '%s'\n", entry->key);
> ret = AVERROR_OPTION_NOT_FOUND;
> - goto fail;
> + goto end;
> }
>
> - *ravf = avf2;
> - return 0;
> -
> -fail:
> +end:
> + av_free(format);
> av_dict_free(&options);
> return ret;
> }
> @@ -158,14 +253,48 @@ static void close_slaves(AVFormatContext *avf)
> {
> TeeContext *tee = avf->priv_data;
> AVFormatContext *avf2;
> - unsigned i;
> + unsigned i, j;
>
> for (i = 0; i < tee->nb_slaves; i++) {
> - avf2 = tee->slaves[i];
> + avf2 = tee->slaves[i].avf;
> +
> + for (j = 0; j < avf2->nb_streams; j++) {
> + AVBitStreamFilterContext *bsf_next, *bsf = tee->slaves[i].bsfs[j];
> + while (bsf) {
> + bsf_next = bsf->next;
> + av_bitstream_filter_close(bsf);
> + bsf = bsf_next;
> + }
> + }
> +
> avio_close(avf2->pb);
> avf2->pb = NULL;
> avformat_free_context(avf2);
> - tee->slaves[i] = NULL;
> + tee->slaves[i].avf = NULL;
> + }
> +}
> +
> +static void log_slave(TeeSlave *slave, void *log_ctx, int log_level)
> +{
> + int i;
> + av_log(log_ctx, log_level, "filename:'%s' format:%s\n",
> + slave->avf->filename, slave->avf->oformat->name);
> + for (i = 0; i < slave->avf->nb_streams; i++) {
> + AVStream *st = slave->avf->streams[i];
> + AVBitStreamFilterContext *bsf = slave->bsfs[i];
> +
> + av_log(log_ctx, log_level, " stream:%d codec:%s type:%s",
> + i, avcodec_get_name(st->codec->codec_id),
> + av_get_media_type_string(st->codec->codec_type));
> + if (bsf) {
> + av_log(log_ctx, log_level, " bsfs:");
> + while (bsf) {
> + av_log(log_ctx, log_level, "%s%s",
> + bsf->filter->name, bsf->next ? "," : "");
> + bsf = bsf->next;
> + }
> + }
> + av_log(log_ctx, log_level, "\n");
> }
> }
>
> @@ -195,6 +324,7 @@ static int tee_write_header(AVFormatContext *avf)
> for (i = 0; i < nb_slaves; i++) {
> if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0)
> goto fail;
> + log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);
> av_freep(&slaves[i]);
> }
>
> @@ -208,6 +338,46 @@ fail:
> return ret;
> }
>
> +static int filter_packet(void *log_ctx, AVPacket *pkt,
> + AVFormatContext *fmt_ctx, AVBitStreamFilterContext *bsf_ctx)
> +{
> + AVCodecContext *enc_ctx = fmt_ctx->streams[pkt->stream_index]->codec;
> + int ret;
> +
> + while (bsf_ctx) {
> + AVPacket new_pkt = *pkt;
> + ret = av_bitstream_filter_filter(bsf_ctx, enc_ctx, NULL,
> + &new_pkt.data, &new_pkt.size,
> + pkt->data, pkt->size,
> + pkt->flags & AV_PKT_FLAG_KEY);
> + if (ret == 0 && new_pkt.data != pkt->data && new_pkt.destruct) {
> + if ((ret = av_copy_packet(&new_pkt, pkt)) < 0)
> + break;
> + ret = 1;
> + }
> +
> + if (ret > 0) {
> + av_free_packet(pkt);
> + new_pkt.buf = av_buffer_create(new_pkt.data, new_pkt.size,
> + av_buffer_default_free, NULL, 0);
> + if (!new_pkt.buf)
> + break;
> + }
> + *pkt = new_pkt;
> +
> + bsf_ctx = bsf_ctx->next;
> + }
> +
> + if (ret < 0) {
> + av_log(log_ctx, AV_LOG_ERROR,
> + "Failed to filter bitstream with filter %s for stream %d in file '%s' with codec %s\n",
> + bsf_ctx->filter->name, pkt->stream_index, fmt_ctx->filename,
> + avcodec_get_name(enc_ctx->codec_id));
> + }
> +
> + return ret;
> +}
> +
> static int tee_write_trailer(AVFormatContext *avf)
> {
> TeeContext *tee = avf->priv_data;
> @@ -216,7 +386,7 @@ static int tee_write_trailer(AVFormatContext *avf)
> unsigned i;
>
> for (i = 0; i < tee->nb_slaves; i++) {
> - avf2 = tee->slaves[i];
> + avf2 = tee->slaves[i].avf;
> if ((ret = av_write_trailer(avf2)) < 0)
> if (!ret_all)
> ret_all = ret;
> @@ -241,7 +411,7 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
> AVRational tb, tb2;
>
> for (i = 0; i < tee->nb_slaves; i++) {
> - avf2 = tee->slaves[i];
> + avf2 = tee->slaves[i].avf;
> s = pkt->stream_index;
> if (s >= avf2->nb_streams) {
> if (!ret_all)
> @@ -259,6 +429,8 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
> pkt2.pts = av_rescale_q(pkt->pts, tb, tb2);
> pkt2.dts = av_rescale_q(pkt->dts, tb, tb2);
> pkt2.duration = av_rescale_q(pkt->duration, tb, tb2);
> +
> + filter_packet(avf2, &pkt2, avf2, tee->slaves[i].bsfs[s]);
> if ((ret = av_interleaved_write_frame(avf2, &pkt2)) < 0)
> if (!ret_all)
> ret_all = ret;
No other remarks, thanks.
Regards,
--
Nicolas George
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