[FFmpeg-devel] [PATCH v4 2/2] rtp: rfc4175: add handler for YCbCr-4:2:2

√Čloi Bail eloi.bail at savoirfairelinux.com
Tue Oct 24 18:11:47 EEST 2017


----- On Apr 5, 2017, at 6:11 PM, Rostislav Pehlivanov <atomnuker at gmail.com> wrote: 

> On 31 March 2017 at 16:36, Damien Riegel <damien.riegel at savoirfairelinux.com
> > wrote:

> > This adds partial support for the RFC 4175 (raw video over RTP). The
> > only supported formats are the YCbCr-4:2:2 8 bit because it's natively
> > supported by FFmpeg with pixel format UYVY, and 10 bit which requires
> > the vrawdepay codec to convert the payload in a format handled by
> > FFmpeg.

> > Signed-off-by: Damien Riegel <damien.riegel at savoirfairelinux.com>
> > ---
> > Changes in v4:
> > - use strncmp for string comparisons
> > - use AVERROR_INVALIDDATA instead of custom error codes

> > Changes in v3:
> > - rename rawvideo to rfc4175
> > - set pixel format in codec parameters
> > - add additional check to prevent buffer overflow

> > libavformat/Makefile | 1 +
> > libavformat/rtpdec.c | 1 +
> > libavformat/rtpdec_formats.h | 1 +
> > libavformat/rtpdec_rfc4175.c | 236 ++++++++++++++++++++++++++++++
> > +++++++++++++
> > 4 files changed, 239 insertions(+)
> > create mode 100644 libavformat/rtpdec_rfc4175.c

> > diff --git a/libavformat/Makefile b/libavformat/Makefile
> > index f56ef16532..a1dae894fe 100644
> > --- a/libavformat/Makefile
> > +++ b/libavformat/Makefile
> > @@ -55,6 +55,7 @@ OBJS-$(CONFIG_RTPDEC) += rdt.o
> > \
> > rtpdec_qcelp.o \
> > rtpdec_qdm2.o \
> > rtpdec_qt.o \
> > + rtpdec_rfc4175.o \
> > rtpdec_svq3.o \
> > rtpdec_vc2hq.o \
> > rtpdec_vp8.o \
> > diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
> > index 53cdad7396..4acb1ca629 100644
> > --- a/libavformat/rtpdec.c
> > +++ b/libavformat/rtpdec.c
> > @@ -114,6 +114,7 @@ void ff_register_rtp_dynamic_payload_handlers(void)
> > ff_register_dynamic_payload_handler(&ff_qt_rtp_vid_handler);
> > ff_register_dynamic_payload_handler(&ff_quicktime_rtp_aud_handler);
> > ff_register_dynamic_payload_handler(&ff_quicktime_rtp_vid_handler);
> > + ff_register_dynamic_payload_handler(&ff_rfc4175_rtp_handler);
> > ff_register_dynamic_payload_handler(&ff_svq3_dynamic_handler);
> > ff_register_dynamic_payload_handler(&ff_theora_dynamic_handler);
> > ff_register_dynamic_payload_handler(&ff_vc2hq_dynamic_handler);
> > diff --git a/libavformat/rtpdec_formats.h b/libavformat/rtpdec_formats.h
> > index 3292a3d265..a436c9d62c 100644
> > --- a/libavformat/rtpdec_formats.h
> > +++ b/libavformat/rtpdec_formats.h
> > @@ -82,6 +82,7 @@ extern RTPDynamicProtocolHandler ff_qt_rtp_aud_handler;
> > extern RTPDynamicProtocolHandler ff_qt_rtp_vid_handler;
> > extern RTPDynamicProtocolHandler ff_quicktime_rtp_aud_handler;
> > extern RTPDynamicProtocolHandler ff_quicktime_rtp_vid_handler;
> > +extern RTPDynamicProtocolHandler ff_rfc4175_rtp_handler;
> > extern RTPDynamicProtocolHandler ff_svq3_dynamic_handler;
> > extern RTPDynamicProtocolHandler ff_theora_dynamic_handler;
> > extern RTPDynamicProtocolHandler ff_vc2hq_dynamic_handler;
> > diff --git a/libavformat/rtpdec_rfc4175.c b/libavformat/rtpdec_rfc4175.c
> > new file mode 100644
> > index 0000000000..498381dfd3
> > --- /dev/null
> > +++ b/libavformat/rtpdec_rfc4175.c
> > @@ -0,0 +1,236 @@
> > +/*
> > + * RTP Depacketization of RAW video (TR-03)
> > + * Copyright (c) 2016 Savoir-faire Linux, Inc
> > + *
> > + * This file is part of FFmpeg.
> > + *
> > + * FFmpeg is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2.1 of the License, or (at your option) any later version.
> > + *
> > + * FFmpeg is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with FFmpeg; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> > 02110-1301 USA
> > + */
> > +
> > +/* Development sponsored by CBC/Radio-Canada */
> > +
> > +#include "avio_internal.h"
> > +#include "rtpdec_formats.h"
> > +#include "libavutil/avstring.h"
> > +#include "libavutil/pixdesc.h"
> > +
> > +struct PayloadContext {
> > + char *sampling;
> > + int depth;
> > + int width;
> > + int height;
> > +
> > + uint8_t *frame;
> > + unsigned int frame_size;
> > + unsigned int pgroup; /* size of the pixel group in bytes */
> > + unsigned int xinc;
> > +
> > + uint32_t timestamp;
> > +};
> > +
> > +static int rfc4175_parse_format(AVStream *stream, PayloadContext *data)
> > +{
> > + enum AVPixelFormat pixfmt = AV_PIX_FMT_NONE;
> > + int bits_per_sample = 0;
> > + int tag = 0;
> > +
> > + if (!strncmp(data->sampling, "YCbCr-4:2:2", 11)) {
> > + tag = MKTAG('U', 'Y', 'V', 'Y');
> > + data->xinc = 2;
> > +
> > + if (data->depth == 8) {
> > + data->pgroup = 4;
> > + bits_per_sample = 16;
> > + pixfmt = AV_PIX_FMT_UYVY422;
> > + } else if (data->depth == 10) {
> > + data->pgroup = 5;
> > + bits_per_sample = 20;
> > + pixfmt = AV_PIX_FMT_YUV422P10;
> > + } else {
> > + return AVERROR_INVALIDDATA;
> > + }
> > + } else {
> > + return AVERROR_INVALIDDATA;
> > + }
> > +
> > + stream->codecpar->format = pixfmt;
> > + stream->codecpar->codec_tag = tag;
> > + stream->codecpar->bits_per_coded_sample = bits_per_sample;
> > + data->frame_size = data->width * data->height * data->pgroup /
> > data->xinc;
> > +
> > + return 0;
> > +}
> > +
> > +static int rfc4175_parse_fmtp(AVFormatContext *s, AVStream *stream,
> > + PayloadContext *data, const char *attr,
> > + const char *value)
> > +{
> > + if (!strncmp(attr, "width", 5))
> > + data->width = atoi(value);
> > + else if (!strncmp(attr, "height", 6))
> > + data->height = atoi(value);
> > + else if (!strncmp(attr, "sampling", 8))
> > + data->sampling = av_strdup(value);
> > + else if (!strncmp(attr, "depth", 5))
> > + data->depth = atoi(value);
> > +
> > + return 0;
> > +}
> > +
> > +static int rfc4175_parse_sdp_line(AVFormatContext *s, int st_index,
> > + PayloadContext *data, const char *line)
> > +{
> > + const char *p;
> > +
> > + if (st_index < 0)
> > + return 0;
> > +
> > + if (av_strstart(line, "fmtp:", &p)) {
> > + AVStream *stream = s->streams[st_index];
> > + int ret = ff_parse_fmtp(s, stream, data, p, rfc4175_parse_fmtp);
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > +
> > + if (!data->sampling || !data->depth || !data->width ||
> > !data->height)
> > + return -1;
> > +
> > + stream->codecpar->width = data->width;
> > + stream->codecpar->height = data->height;
> > +
> > + ret = rfc4175_parse_format(stream, data);
> > + av_freep(&data->sampling);
> > +
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int rfc4175_finalize_packet(PayloadContext *data, AVPacket *pkt,
> > + int stream_index)
> > +{
> > + int ret;
> > +
> > + pkt->stream_index = stream_index;
> > + ret = av_packet_from_data(pkt, data->frame, data->frame_size);
> > + if (ret < 0) {
> > + av_freep(&data->frame);
> > + }
> > +
> > + data->frame = NULL;
> > +
> > + return ret;
> > +}
> > +
> > +static int rfc4175_handle_packet(AVFormatContext *ctx, PayloadContext
> > *data,
> > + AVStream *st, AVPacket *pkt, uint32_t
> > *timestamp,
> > + const uint8_t * buf, int len,
> > + uint16_t seq, int flags)
> > +{
> > + int length, line, offset, cont;
> > + const uint8_t *headers = buf + 2; /* skip extended seqnum */
> > + const uint8_t *payload = buf + 2;
> > + int payload_len = len - 2;
> > + int missed_last_packet = 0;
> > +
> > + uint8_t *dest;
> > +
> > + if (*timestamp != data->timestamp) {
> > + if (data->frame) {
> > + /*
> > + * if we're here, it means that two RTP packets didn't have
> > the
> > + * same timestamp, which is a sign that they were packets
> > from two
> > + * different frames, but we didn't get the flag
> > RTP_FLAG_MARKER on
> > + * the first one of these frames (last packet of a frame).
> > + * Finalize the previous frame anyway by filling the AVPacket.
> > + */
> > + av_log(ctx, AV_LOG_ERROR, "Missed previous RTP Marker\n");
> > + missed_last_packet = 1;
> > + rfc4175_finalize_packet(data, pkt, st->index);
> > + }
> > +
> > + data->frame = av_malloc(data->frame_size);
> > +
> > + data->timestamp = *timestamp;
> > +
> > + if (!data->frame) {
> > + av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
> > + return AVERROR(ENOMEM);
> > + }
> > + }
> > +
> > + /*
> > + * looks for the 'Continuation bit' in scan lines' headers
> > + * to find where data start
> > + */
> > + do {
> > + if (payload_len < 6)
> > + return AVERROR_INVALIDDATA;
> > +
> > + cont = payload[4] & 0x80;
> > + payload += 6;
> > + payload_len -= 6;
> > + } while (cont);
> > +
> > + /* and now iterate over every scan lines */
> > + do {
> > + int copy_offset;
> > +
> > + if (payload_len < data->pgroup)
> > + return AVERROR_INVALIDDATA;
> > +
> > + length = (headers[0] << 8) | headers[1];
> > + line = ((headers[2] & 0x7f) << 8) | headers[3];
> > + offset = ((headers[4] & 0x7f) << 8) | headers[5];
> > + cont = headers[4] & 0x80;
> > + headers += 6;
> > +
> > + if (length % data->pgroup)
> > + return AVERROR_INVALIDDATA;
> > +
> > + if (length > payload_len)
> > + length = payload_len;
> > +
> > + /* prevent ill-formed packets to write after buffer's end */
> > + copy_offset = (line * data->width + offset) * data->pgroup /
> > data->xinc;
> > + if (copy_offset + length > data->frame_size)
> > + return AVERROR_INVALIDDATA;
> > +
> > + dest = data->frame + copy_offset;
> > + memcpy(dest, payload, length);
> > +
> > + payload += length;
> > + payload_len -= length;
> > + } while (cont);
> > +
> > + if ((flags & RTP_FLAG_MARKER)) {
> > + return rfc4175_finalize_packet(data, pkt, st->index);
> > + } else if (missed_last_packet) {
> > + return 0;
> > + }
> > +
> > + return AVERROR(EAGAIN);
> > +}
> > +
> > +RTPDynamicProtocolHandler ff_rfc4175_rtp_handler = {
> > + .enc_name = "raw",
> > + .codec_type = AVMEDIA_TYPE_VIDEO,
> > + .codec_id = AV_CODEC_ID_BITPACKED,
> > + .priv_data_size = sizeof(PayloadContext),
> > + .parse_sdp_a_line = rfc4175_parse_sdp_line,
> > + .parse_packet = rfc4175_handle_packet,
> > +};
> > --
> > 2.12.0

> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel


> Pushed, thanks
Hi, 

I am surprised to see no mention on this work in changelog [1]. 

I would put: "partial support of SMPTE 2110-20 (RFC4175)". 

Thanks, 

Eloi 

[1]: https://github.com/FFmpeg/FFmpeg/blob/master/Changelog 


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