[FFmpeg-devel] [PATCH v4 3/3] avformat/tee: Handling slave failure in tee muxer

Jan Sebechlebsky sebechlebskyjan at gmail.com
Wed Apr 6 01:29:10 CEST 2016


Hello,
can the patchset be applied as it is now? ( I don't want to hurry you, 
just reminding :) )

Jan S.
On 04/04/2016 12:06 AM, sebechlebskyjan at gmail.com wrote:
> From: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
>
> Adds per slave option 'onfail' to the tee muxer allowing an output to
> fail,so other slave outputs can continue.
>
> Signed-off-by: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
> ---
>   I've just added topic to commit message title as Marton Balint suggested.
>
>   doc/muxers.texi   | 14 ++++++++
>   libavformat/tee.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++------
>   2 files changed, 100 insertions(+), 10 deletions(-)
>
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 2aafbad..2d63083 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -1372,6 +1372,12 @@ Select the streams that should be mapped to the slave output,
>   specified by a stream specifier. If not specified, this defaults to
>   all the input streams. You may use multiple stream specifiers
>   separated by commas (@code{,}) e.g.: @code{a:0,v}
> +
> + at item onfail
> +Specify behaviour on output failure. This can be set to either @code{abort} (which is
> +default) or @code{ignore}. @code{abort} will cause whole process to fail in case of failure
> +on this slave output. @code{ignore} will ignore failure on this output, so other outputs
> +will continue without being affected.
>   @end table
>   
>   @subsection Examples
> @@ -1386,6 +1392,14 @@ ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
>   @end example
>   
>   @item
> +As above, but continue streaming even if output to local file fails
> +(for example local drive fills up):
> + at example
> +ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
> +  "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
> + at end example
> +
> + at item
>   Use @command{ffmpeg} to encode the input, and send the output
>   to three different destinations. The @code{dump_extra} bitstream
>   filter is used to add extradata information to all the output video
> diff --git a/libavformat/tee.c b/libavformat/tee.c
> index d823805..50aaf9f 100644
> --- a/libavformat/tee.c
> +++ b/libavformat/tee.c
> @@ -29,10 +29,20 @@
>   
>   #define MAX_SLAVES 16
>   
> +typedef enum {
> +    ON_SLAVE_FAILURE_ABORT  = 1,
> +    ON_SLAVE_FAILURE_IGNORE = 2
> +} SlaveFailurePolicy;
> +
> +#define DEFAULT_SLAVE_FAILURE_POLICY ON_SLAVE_FAILURE_ABORT
> +
>   typedef struct {
>       AVFormatContext *avf;
>       AVBitStreamFilterContext **bsfs; ///< bitstream filters per stream
>   
> +    SlaveFailurePolicy on_fail;
> +    unsigned char is_alive;
> +
>       /** map from input to output streams indexes,
>        * disabled output streams are set to -1 */
>       int *stream_map;
> @@ -41,6 +51,7 @@ typedef struct {
>   typedef struct TeeContext {
>       const AVClass *class;
>       unsigned nb_slaves;
> +    unsigned nb_alive;
>       TeeSlave slaves[MAX_SLAVES];
>   } TeeContext;
>   
> @@ -135,6 +146,18 @@ end:
>       return ret;
>   }
>   
> +static inline int parse_slave_failure_policy_option(const char *opt)
> +{
> +    if (!opt) {
> +        return DEFAULT_SLAVE_FAILURE_POLICY;
> +    } else if (!av_strcasecmp("abort", opt)) {
> +        return ON_SLAVE_FAILURE_ABORT;
> +    } else if (!av_strcasecmp("ignore", opt)) {
> +        return ON_SLAVE_FAILURE_IGNORE;
> +    }
> +    return 0;
> +}
> +
>   static void close_slave(TeeSlave *tee_slave)
>   {
>       AVFormatContext *avf;
> @@ -165,7 +188,8 @@ static void close_slaves(AVFormatContext *avf)
>       unsigned i;
>   
>       for (i = 0; i < tee->nb_slaves; i++) {
> -        close_slave(&tee->slaves[i]);
> +        if (tee->slaves[i].is_alive)
> +            close_slave(&tee->slaves[i]);
>       }
>   }
>   
> @@ -175,7 +199,7 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>       AVDictionary *options = NULL;
>       AVDictionaryEntry *entry;
>       char *filename;
> -    char *format = NULL, *select = NULL;
> +    char *format = NULL, *select = NULL, *on_fail = NULL;
>       AVFormatContext *avf2 = NULL;
>       AVStream *st, *st2;
>       int stream_count;
> @@ -195,6 +219,17 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>   
>       STEAL_OPTION("f", format);
>       STEAL_OPTION("select", select);
> +    STEAL_OPTION("onfail", on_fail);
> +
> +    tee_slave->on_fail = parse_slave_failure_policy_option(on_fail);
> +    if (!tee_slave->on_fail) {
> +        av_log(avf, AV_LOG_ERROR,
> +               "Invalid onfail option value, valid options are 'abort' and 'ignore'\n");
> +        ret = AVERROR(EINVAL);
> +        /* Set failure behaviour to abort, so invalid option error will not be ignored */
> +        tee_slave->on_fail = ON_SLAVE_FAILURE_ABORT;
> +        goto end;
> +    }
>   
>       ret = avformat_alloc_output_context2(&avf2, NULL, format, filename);
>       if (ret < 0)
> @@ -339,8 +374,11 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>       }
>   
>   end:
> +    if (ret < 0)
> +        close_slave(tee_slave);
>       av_free(format);
>       av_free(select);
> +    av_free(on_fail);
>       av_dict_free(&options);
>       av_freep(&tmp_select);
>       return ret;
> @@ -370,6 +408,31 @@ static void log_slave(TeeSlave *slave, void *log_ctx, int log_level)
>       }
>   }
>   
> +static int tee_process_slave_failure(AVFormatContext *avf, unsigned slave_idx,
> +                                     int err_n, unsigned char needs_closing)
> +{
> +    TeeContext *tee = avf->priv_data;
> +    TeeSlave *tee_slave = &tee->slaves[slave_idx];
> +
> +    tee_slave->is_alive = 0;
> +    tee->nb_alive--;
> +
> +    if (needs_closing)
> +        close_slave(tee_slave);
> +
> +    if (!tee->nb_alive) {
> +        av_log(avf, AV_LOG_ERROR, "All tee outputs failed.\n");
> +        return err_n;
> +    } else if (tee_slave->on_fail == ON_SLAVE_FAILURE_ABORT) {
> +        av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed,aborting.\n", slave_idx);
> +        return err_n;
> +    } else {
> +        av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed, continuing with %u/%u slaves.\n",
> +               slave_idx, tee->nb_alive, tee->nb_slaves);
> +        return 0;
> +    }
> +}
> +
>   static int tee_write_header(AVFormatContext *avf)
>   {
>       TeeContext *tee = avf->priv_data;
> @@ -393,19 +456,25 @@ static int tee_write_header(AVFormatContext *avf)
>               filename++;
>       }
>   
> +    tee->nb_slaves = tee->nb_alive = nb_slaves;
> +
>       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);
> +        if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0) {
> +            ret = tee_process_slave_failure(avf, i , ret, 0);
> +            if (ret < 0)
> +                goto fail;
> +        } else {
> +            log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);
> +            tee->slaves[i].is_alive = 1;
> +        }
>           av_freep(&slaves[i]);
>       }
>   
> -    tee->nb_slaves = nb_slaves;
> -
>       for (i = 0; i < avf->nb_streams; i++) {
>           int j, mapped = 0;
>           for (j = 0; j < tee->nb_slaves; j++)
> -            mapped += tee->slaves[j].stream_map[i] >= 0;
> +            if (tee->slaves[j].is_alive)
> +                mapped += tee->slaves[j].stream_map[i] >= 0;
>           if (!mapped)
>               av_log(avf, AV_LOG_WARNING, "Input stream #%d is not mapped "
>                      "to any slave.\n", i);
> @@ -427,6 +496,8 @@ static int tee_write_trailer(AVFormatContext *avf)
>       unsigned i;
>   
>       for (i = 0; i < tee->nb_slaves; i++) {
> +        if (!tee->slaves[i].is_alive)
> +            continue;
>           avf2 = tee->slaves[i].avf;
>           if ((ret = av_write_trailer(avf2)) < 0)
>               if (!ret_all)
> @@ -449,6 +520,9 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
>       AVRational tb, tb2;
>   
>       for (i = 0; i < tee->nb_slaves; i++) {
> +        if (!tee->slaves[i].is_alive)
> +            continue;
> +
>           avf2 = tee->slaves[i].avf;
>           s = pkt->stream_index;
>           s2 = tee->slaves[i].stream_map[s];
> @@ -470,9 +544,11 @@ static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
>   
>           if ((ret = av_apply_bitstream_filters(avf2->streams[s2]->codec, &pkt2,
>                                                 tee->slaves[i].bsfs[s2])) < 0 ||
> -            (ret = av_interleaved_write_frame(avf2, &pkt2)) < 0)
> -            if (!ret_all)
> +            (ret = av_interleaved_write_frame(avf2, &pkt2)) < 0) {
> +            ret = tee_process_slave_failure(avf, i, ret, 1);
> +            if (!ret_all && ret < 0)
>                   ret_all = ret;
> +        }
>       }
>       return ret_all;
>   }



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