[FFmpeg-devel] [PATCH v8 3/6] avformat/flvenc: support mux av1 in enhanced flv

Gyan Doshi ffmpeg at gyani.pro
Tue May 9 13:48:03 EEST 2023



On 2023-05-09 04:05 pm, Neal Gompa wrote:
> On Tue, May 9, 2023 at 12:14 AM Gyan Doshi <ffmpeg at gyani.pro> wrote:
>>
>>
>> On 2023-05-09 08:11 am, Neal Gompa wrote:
>>> On Mon, May 8, 2023 at 9:55 PM Steven Liu <lingjiujianke at gmail.com> wrote:
>>>> Neal Gompa <ngompa13 at gmail.com> 于2023年5月9日周二 07:08写道:
>>>>> On Thu, Apr 13, 2023 at 5:45 AM Steven Liu <lq at chinaffmpeg.org> wrote:
>>>>>> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
>>>>>> ---
>>>>>>    libavformat/flvenc.c | 25 ++++++++++++++++++++-----
>>>>>>    1 file changed, 20 insertions(+), 5 deletions(-)
>>>>>>
>>>>>> diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
>>>>>> index 57a26245ff..7b43ecaefa 100644
>>>>>> --- a/libavformat/flvenc.c
>>>>>> +++ b/libavformat/flvenc.c
>>>>>> @@ -28,6 +28,7 @@
>>>>>>    #include "libavcodec/mpeg4audio.h"
>>>>>>    #include "avio.h"
>>>>>>    #include "avc.h"
>>>>>> +#include "av1.h"
>>>>>>    #include "hevc.h"
>>>>>>    #include "avformat.h"
>>>>>>    #include "flv.h"
>>>>>> @@ -48,6 +49,7 @@ static const AVCodecTag flv_video_codec_ids[] = {
>>>>>>        { AV_CODEC_ID_VP6A,     FLV_CODECID_VP6A },
>>>>>>        { AV_CODEC_ID_H264,     FLV_CODECID_H264 },
>>>>>>        { AV_CODEC_ID_HEVC,     MKBETAG('h', 'v', 'c', '1') },
>>>>>> +    { AV_CODEC_ID_AV1,      MKBETAG('a', 'v', '0', '1') },
>>>>>>        { AV_CODEC_ID_NONE,     0 }
>>>>>>    };
>>>>>>
>>>>>> @@ -494,7 +496,8 @@ static void flv_write_codec_header(AVFormatContext* s, AVCodecParameters* par, i
>>>>>>        FLVContext *flv = s->priv_data;
>>>>>>
>>>>>>        if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
>>>>>> -            || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>> +            || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC
>>>>>> +            || par->codec_id == AV_CODEC_ID_AV1) {
>>>>>>            int64_t pos;
>>>>>>            avio_w8(pb,
>>>>>>                    par->codec_type == AVMEDIA_TYPE_VIDEO ?
>>>>>> @@ -540,6 +543,9 @@ static void flv_write_codec_header(AVFormatContext* s, AVCodecParameters* par, i
>>>>>>                if (par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>>                    avio_w8(pb, FLV_IS_EX_HEADER | PacketTypeSequenceStart); // ExVideoTagHeader mode with PacketTypeSequenceStart
>>>>>>                    avio_write(pb, "hvc1", 4);
>>>>>> +            } else if (par->codec_id == AV_CODEC_ID_AV1) {
>>>>>> +                avio_w8(pb, FLV_IS_EX_HEADER | PacketTypeSequenceStart);
>>>>>> +                avio_write(pb, "av01", 4);
>>>>>>                } else {
>>>>>>                    avio_w8(pb, par->codec_tag | FLV_FRAME_KEY); // flags
>>>>>>                    avio_w8(pb, 0); // AVC sequence header
>>>>>> @@ -548,6 +554,8 @@ static void flv_write_codec_header(AVFormatContext* s, AVCodecParameters* par, i
>>>>>>
>>>>>>                if (par->codec_id == AV_CODEC_ID_HEVC)
>>>>>>                    ff_isom_write_hvcc(pb, par->extradata, par->extradata_size, 0);
>>>>>> +            else if (par->codec_id == AV_CODEC_ID_AV1)
>>>>>> +                ff_isom_write_av1c(pb, par->extradata, par->extradata_size, 1);
>>>>>>                else
>>>>>>                    ff_isom_write_avcc(pb, par->extradata, par->extradata_size);
>>>>>>            }
>>>>>> @@ -640,7 +648,8 @@ static int flv_init(struct AVFormatContext *s)
>>>>>>
>>>>>>                if (par->codec_id == AV_CODEC_ID_MPEG4 ||
>>>>>>                    par->codec_id == AV_CODEC_ID_H263 ||
>>>>>> -                par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>> +                par->codec_id == AV_CODEC_ID_HEVC ||
>>>>>> +                par->codec_id == AV_CODEC_ID_AV1) {
>>>>>>                    int error = s->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL;
>>>>>>                    av_log(s, error ? AV_LOG_ERROR : AV_LOG_WARNING,
>>>>>>                           "Codec %s is not supported in the official FLV specification,\n", avcodec_get_name(par->codec_id));
>>>>>> @@ -848,13 +857,15 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
>>>>>>        if (par->codec_id == AV_CODEC_ID_VP6F || par->codec_id == AV_CODEC_ID_VP6A ||
>>>>>>            par->codec_id == AV_CODEC_ID_VP6  || par->codec_id == AV_CODEC_ID_AAC)
>>>>>>            flags_size = 2;
>>>>>> -    else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC)
>>>>>> +    else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 ||
>>>>>> +             par->codec_id == AV_CODEC_ID_HEVC || par->codec_id == AV_CODEC_ID_AV1)
>>>>>>            flags_size = 5;
>>>>>>        else
>>>>>>            flags_size = 1;
>>>>>>
>>>>>>        if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
>>>>>> -            || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>> +            || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC
>>>>>> +            || par->codec_id == AV_CODEC_ID_AV1) {
>>>>>>            size_t side_size;
>>>>>>            uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
>>>>>>            if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) {
>>>>>> @@ -874,7 +885,8 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
>>>>>>                   "Packets are not in the proper order with respect to DTS\n");
>>>>>>            return AVERROR(EINVAL);
>>>>>>        }
>>>>>> -    if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>> +    if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 ||
>>>>>> +        par->codec_id == AV_CODEC_ID_HEVC ||  par->codec_id == AV_CODEC_ID_AV1) {
>>>>>>            if (pkt->pts == AV_NOPTS_VALUE) {
>>>>>>                av_log(s, AV_LOG_ERROR, "Packet is missing PTS\n");
>>>>>>                return AVERROR(EINVAL);
>>>>>> @@ -987,6 +999,9 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
>>>>>>            if (par->codec_id == AV_CODEC_ID_HEVC) {
>>>>>>                avio_w8(pb, FLV_IS_EX_HEADER | PacketTypeCodedFramesX); // ExVideoTagHeader mode with PacketTypeCodedFramesX
>>>>>>                avio_write(pb, "hvc1", 4);
>>>>>> +        } else if (par->codec_id == AV_CODEC_ID_AV1) {
>>>>>> +            avio_w8(pb, FLV_IS_EX_HEADER | PacketTypeCodedFrames);
>>>>>> +            avio_write(pb, "av01", 4);
>>>>>>            } else {
>>>>>>                avio_w8(pb, flags);
>>>>>>            }
>>>>>> --
>>>>>> 2.40.0
>>>>>>
>>>>> I tested this by applying the patches on top of ffmpeg 6.0 and it
>>>>> doesn't seem to work:
>>>>>
>>>>>     libavutil      58.  2.100 / 58.  2.100
>>>>>     libavcodec     60.  3.100 / 60.  3.100
>>>>>     libavformat    60.  3.100 / 60.  3.100
>>>>>     libavdevice    60.  1.100 / 60.  1.100
>>>>>     libavfilter     9.  3.100 /  9.  3.100
>>>>>     libswscale      7.  1.100 /  7.  1.100
>>>>>     libswresample   4. 10.100 /  4. 10.100
>>>>>     libpostproc    57.  1.100 / 57.  1.100
>>>>> [libdav1d @ 0x55c9ea8cae80] libdav1d 1.1.0
>>>>> Input #0, matroska,webm, from '2023-05-08 18-52-42.mkv':
>>>>>     Metadata:
>>>>>       ENCODER         : Lavf60.3.100
>>>>>     Duration: 00:02:00.53, start: 0.000000, bitrate: 1155 kb/s
>>>>>     Stream #0:0: Video: av1 (Main), yuv420p(tv, bt709), 1280x720, 30
>>>>> fps, 30 tbr, 1k tbn
>>>>>       Metadata:
>>>>>         DURATION        : 00:02:00.533000000
>>>>>     Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp
>>>>>       Metadata:
>>>>>         title           : Track1
>>>>>         DURATION        : 00:02:00.533000000
>>>>> [flv @ 0x55c9ea936140] Codec av1 is not supported in the official FLV
>>>>> specification,
>>>>> [flv @ 0x55c9ea936140] use vstrict=-1 / -strict -1 to use it anyway.
>>>> Pay attention this warning message.
>>>>
>>>>> [out#0/flv @ 0x55c9ea8cda80] Could not write header (incorrect codec
>>>>> parameters ?): Invalid argument
>>>>> [aost#0:1/copy @ 0x55c9ea97ae00] Error initializing output stream:
>>>>> Stream mapping:
>>>>>     Stream #0:0 -> #0:0 (copy)
>>>>>     Stream #0:1 -> #0:1 (copy)
>>>>>       Last message repeated 1 times
>>> Well, this is my command:
>>>
>>> $ ffmpeg -i "input.mkv" -vcodec copy -acodec copy "output.flv"
>>>
>>> What should I be doing instead?
>>     ffmpeg -i "input.mkv" -vcodec copy -acodec copy -strict -1 "output.flv"
>>
> That defeats the point of this patch. This patch adds proper support
> for AV1 to the FLV code, so it should not need that.

This patch does not add HEVC or AV1 support to the FLV *specification*, 
hence the guard.

Regards,
Gyan



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