[vlc-devel] [vlc-commits] stream_out: rtp: add support for HEVC

Filip Roséen filip at atch.se
Sun May 21 16:35:41 CEST 2017


Hi Francois,

On 2017-05-21 13:48, Francois Cartegnie wrote:

> vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Sun May 21 14:17:43 2017 +0200| [d2279d9de48eb3199000f5908ecc7e7ff1667ce6] | committer: Francois Cartegnie
> 
> stream_out: rtp: add support for HEVC
> 
> > http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=d2279d9de48eb3199000f5908ecc7e7ff1667ce6
> ---
> 
>  modules/stream_out/rtpfmt.c | 212 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 212 insertions(+)
> 
> diff --git a/modules/stream_out/rtpfmt.c b/modules/stream_out/rtpfmt.c
> index 1f4d9a8df5..c5b178f514 100644
> --- a/modules/stream_out/rtpfmt.c
> +++ b/modules/stream_out/rtpfmt.c
> @@ -50,6 +50,7 @@ static int rtp_packetize_mp4a (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_mp4a_latm (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_h263 (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_h264 (sout_stream_id_sys_t *, block_t *);
> +static int rtp_packetize_h265 (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_amr  (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_spx  (sout_stream_id_sys_t *, block_t *);
>  static int rtp_packetize_t140 (sout_stream_id_sys_t *, block_t *);
> @@ -335,6 +336,136 @@ int rtp_get_fmt( vlc_object_t *obj, const es_format_t *p_fmt, const char *mux,
>                  rtp_fmt->fmtp = strdup( "packetization-mode=1" );
>              break;
>  
> +        case VLC_CODEC_HEVC:
> +        {
> +            rtp_fmt->ptname = "H265";
> +            rtp_fmt->pf_packetize = rtp_packetize_h265;
> +            rtp_fmt->fmtp = NULL;
> +
> +            int i_profile = p_fmt->i_profile;
> +            int i_level = p_fmt->i_level;
> +            int i_tiers = -1;
> +            int i_space = -1;
> +
> +            struct nalset_e
> +            {
> +                const uint8_t i_nal;
> +                const uint8_t i_extend;
> +                const char *psz_name;
> +                char *psz_64;
> +            } nalsets[4] = {
> +                { 32, 0, "vps", NULL },
> +                { 33, 0, "sps", NULL },
> +                { 34, 0, "pps", NULL },
> +                { 39, 1, "sei", NULL },
> +            };
> +
> +            if( p_fmt->i_extra > 0 )
> +            {
> +                hxxx_iterator_ctx_t it;

`it` could be declared inside the below *for-loop*, given that it is
reset on every iteration and not used outside of the *loop-body*.

> +                for(int i=0; i<4; i++)
> +                {

The loop condition might benefit from using something like
`ARRAY_SIZE`, so that one gets rid of the somewhat magic `4` (even
though the proximity of `nalset_e` and `i<4` should make it clear why
`4` is used.

> +                    struct nalset_e *set = &nalsets[i];
> +
> +                    hxxx_iterator_init( &it, p_fmt->p_extra, p_fmt->i_extra, 0 );
> +                    const uint8_t *p_nal;
> +                    size_t i_nal;
> +                    while( hxxx_annexb_iterate_next( &it, &p_nal, &i_nal ) )
> +                    {
> +                        const uint8_t i_nal_type = (p_nal[0] & 0x7E) >> 1;
> +                        if( i_nal_type < set->i_nal ||
> +                            i_nal_type > set->i_nal + set->i_extend )
> +                            continue;
> +                        msg_Dbg( obj, "we found a startcode for NAL with TYPE:%" PRIu8, i_nal_type );
> +
> +                        char *psz_temp = vlc_b64_encode_binary( p_nal, i_nal );
> +                        if( psz_temp )
> +                        {
> +                            if( set->psz_64 == NULL )
> +                            {
> +                                set->psz_64 = psz_temp;
> +                            }
> +                            else
> +                            {
> +                                char *psz_merged;
> +                                if( asprintf( &psz_merged, "%s,%s", set->psz_64, psz_temp ) != -1 )
> +                                {
> +                                    free( set->psz_64 );
> +                                    set->psz_64 = psz_merged;
> +                                }
> +                                free( psz_temp );
> +                            }

`vlc_memstream` would greatly simplifly the implementation above.

> +                        }
> +
> +                        if( i_nal_type == 33 && i_nal > 12 )
> +                        {
> +                            if( i_profile < 0 )
> +                                i_profile = p_nal[1] & 0x1F;
> +                            if( i_space < 0 )
> +                                i_space = p_nal[1] >> 6;
> +                            if( i_tiers < 0 )
> +                                i_tiers = !!(p_nal[1] & 0x20);
> +                            if( i_level < 0 )
> +                                i_level = p_nal[12];
> +                        }
> +                    }
> +                }
> +            }
> +
> +            rtp_fmt->fmtp = strdup( "tx-mode=SRST;" );
> +            if( rtp_fmt->fmtp )
> +            {

This entire *if-body* can be a lot simpler if you use `vlc_memstream`,
and the code-size would shrink by a big factor.

> +                char *psz_fmtp;
> +                if( i_profile >= 0 &&
> +                    asprintf( &psz_fmtp, "%sprofile-id=%d;",
> +                                         rtp_fmt->fmtp, i_profile ) != -1 )
> +                {
> +                    free( rtp_fmt->fmtp );
> +                    rtp_fmt->fmtp = psz_fmtp;
> +                }
> +                if( i_level >= 0 &&
> +                    asprintf( &psz_fmtp, "%slevel-id=%d;",
> +                                         rtp_fmt->fmtp, i_level ) != -1 )
> +                {
> +                    free( rtp_fmt->fmtp );
> +                    rtp_fmt->fmtp = psz_fmtp;
> +                }
> +                if( i_tiers >= 0 &&
> +                    asprintf( &psz_fmtp, "%stier-flag=%d;",
> +                                         rtp_fmt->fmtp, i_tiers ) != -1 )
> +                {
> +                    free( rtp_fmt->fmtp );
> +                    rtp_fmt->fmtp = psz_fmtp;
> +                }
> +                if( i_space >= 0 &&
> +                    asprintf( &psz_fmtp, "%sprofile-space=%d;",
> +                                         rtp_fmt->fmtp, i_space ) != -1 )
> +                {
> +                    free( rtp_fmt->fmtp );
> +                    rtp_fmt->fmtp = psz_fmtp;
> +                }
> +
> +                for(int i=0; i<4; i++)
> +                {
> +                    struct nalset_e *set = &nalsets[i];
> +                    if( set->psz_64 &&
> +                        asprintf( &psz_fmtp, "%ssprop-%s=%s;",
> +                                             rtp_fmt->fmtp,
> +                                             set->psz_name,
> +                                             set->psz_64 ) != -1 )
> +                    {
> +                        free( rtp_fmt->fmtp );
> +                        rtp_fmt->fmtp = psz_fmtp;
> +                    }
> +                }
> +            }
> +
> +            for(int i=0; i<4; i++)
> +                free( nalsets[i].psz_64 );
> +
> +            break;
> +        }
> +
>          case VLC_CODEC_MP4V:
>          {
>              rtp_fmt->ptname = "MP4V-ES";
> @@ -1189,6 +1320,87 @@ static int rtp_packetize_h264( sout_stream_id_sys_t *id, block_t *in )
>      return VLC_SUCCESS;
>  }
>  
> +/* rfc7798 */
> +static int
> +rtp_packetize_h265_nal( sout_stream_id_sys_t *id,
> +                        const uint8_t *p_data, size_t i_data, int64_t i_pts,
> +                        int64_t i_dts, bool b_last, int64_t i_length )
> +{
> +    const size_t i_max = rtp_mtu (id); /* payload max in one packet */
> +
> +    if( i_data < 3 )
> +        return VLC_SUCCESS;
> +
> +    /* */
> +    if( i_data <= i_max )
> +    {
> +        /* Single NAL unit packet */
> +        block_t *out = block_Alloc( 12 + i_data );

Missing error-check to see that `block_Alloc` actually succeeded.

> +        out->i_dts    = i_dts;
> +        out->i_length = i_length;
> +
> +        /* */
> +        rtp_packetize_common( id, out, b_last, i_pts );
> +
> +        memcpy( &out->p_buffer[12], p_data, i_data );
> +
> +        rtp_packetize_send( id, out );
> +    }
> +    else
> +    {
> +        const uint16_t i_nal_hdr = (GetWBE(p_data) & 0x81FF) | 0x6200 /* 49 */;
> +        const uint8_t i_nal_type = (p_data[0] & 0x7E) >> 1;
> +
> +        /* FU-A Fragmentation Unit without interleaving */
> +        const size_t i_count = ( i_data-2 + i_max-3 - 2 ) / (i_max-3);
> +
> +        p_data += 2;
> +        i_data -= 2;
> +
> +        for( size_t i = 0; i < i_count; i++ )
> +        {
> +            const size_t i_payload = __MIN( i_data, i_max-3 );
> +            block_t *out = block_Alloc( 12 + 3 + i_payload );

Missing check to see that `block_Alloc` actually succeeded.

> +            out->i_dts    = i_dts + i * i_length / i_count;
> +            out->i_length = i_length / i_count;
> +
> +            /* */
> +            rtp_packetize_common( id, out, (b_last && i_payload == i_data),
> +                                    i_pts );
> +            /* FU indicator */
> +            out->p_buffer[12] = i_nal_hdr >> 8;
> +            out->p_buffer[13] = i_nal_hdr & 0x00FF;
> +            /* FU header */
> +            out->p_buffer[14] = ( i == 0 ? 0x80 : 0x00 ) | ( (i == i_count-1) ? 0x40 : 0x00 )  | i_nal_type;

The above line is very long, and even though an if-branch would result
in more lines, I think it would be easier to grasp the concept of what
is going on. Or simply the below:

    out->p_buffer[14] |= i   ==       0 ? 0x00 : 0x80;
    out->p_buffer[14] |= i+1 != i_count ? 0x00 : 0x40;
    out->p_buffer[14] |= i_nal_type;

At least I find something like that more readable than what is
currently written, though I guess the above is not important as style
preference is of course subjective (but overly long lines is quite
definite).

> +            memcpy( &out->p_buffer[15], p_data, i_payload );
> +
> +            rtp_packetize_send( id, out );
> +
> +            i_data -= i_payload;
> +            p_data += i_payload;
> +        }
> +    }
> +    return VLC_SUCCESS;
> +}
> +
> +static int rtp_packetize_h265( sout_stream_id_sys_t *id, block_t *in )
> +{
> +    hxxx_iterator_ctx_t it;
> +    hxxx_iterator_init( &it, in->p_buffer, in->i_buffer, 0 );
> +
> +    const uint8_t *p_nal;
> +    size_t i_nal;
> +    while( hxxx_annexb_iterate_next( &it, &p_nal, &i_nal ) )
> +    {
> +        rtp_packetize_h265_nal( id, p_nal, i_nal,
> +                (in->i_pts > VLC_TS_INVALID ? in->i_pts : in->i_dts), in->i_dts,
> +                it.p_head + 3 >= it.p_tail, in->i_length * i_nal / in->i_buffer );
> +    }
> +
> +    block_Release(in);
> +    return VLC_SUCCESS;
> +}
> +
>  static int rtp_packetize_amr( sout_stream_id_sys_t *id, block_t *in )
>  {
>      int     i_max   = rtp_mtu (id) - 2; /* payload max in one packet */

Best Regards,\
Filip
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