c++ - 使用 FFmpeg API 创建的 MP4 无法在媒体播放器中播放
问题描述
这几天我一直在为这个问题苦苦挣扎。这里和网络上都发布了类似的问题，但似乎没有一个解决方案对我有用。他们可能已经过时了？
这是我用来生成 MP4 文件的当前代码迭代。
它会生成一个简单的 2 秒 .mp4 文件，无法在我尝试过的任何播放器中播放。如果我通过 FFmpeg 命令行运行该 mp4 文件，它将从中生成完美可播放的电影。所以数据就在那里。
此外，如果您将此代码中的输出文件名从 .mp4 修改为 .avi，则此代码也会生成一个可播放的 avi 文件。所以无论它是什么，它都与 H.264 格式相关联。
我确定我错过了一些简单的东西，但对于我的生活，我无法弄清楚那是什么。
任何帮助将不胜感激！
这是 VC++ 项目的链接。电影制作者.zip
电影制作者.h
#pragma once
extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <libavutil/opt.h>
}
class FMovieMaker
{
public:
~FMovieMaker();
bool Initialize(const char* FileName, int Width = 1920, int Height = 1080, int FPS = 30, int BitRate = 2000);
bool RecordFrame(uint8_t* BGRAData);
bool Finalize();
bool IsInitialized() const { return bInitialized; }
int GetWidth() const { return CodecContext ? CodecContext->width : 0; }
int GetHeight() const { return CodecContext ? CodecContext->height : 0; }
private:
bool EncodeFrame(bool bFinalize);
void Log(const char* fmt, ...);
AVOutputFormat* OutputFormat = nullptr;
AVFormatContext* FormatContext = nullptr;
AVCodecContext* CodecContext = nullptr;
AVFrame* Frame = nullptr;
SwsContext* ColorConverter = nullptr;
int64_t RecordedFrames = 0;
bool bInitialized = false;
};
电影制作者.cpp
#include "MovieMaker.h"
FMovieMaker::~FMovieMaker()
{
if (IsInitialized())
Finalize();
}
bool FMovieMaker::Initialize(const char* FileName, int Width /*= 1920*/, int Height /*= 1080*/, int FPS /*= 30*/, int BitRate /*= 2000*/)
{
OutputFormat = av_guess_format(nullptr, FileName, nullptr);
if (!OutputFormat)
{
Log("Couldn't guess the output format from the filename: %s", FileName);
return false;
}
AVCodecID CodecID = OutputFormat->video_codec;
if (CodecID == AV_CODEC_ID_NONE)
{
Log("Could not determine a codec to use");
return false;
}
/* allocate the output media context */
int ErrorCode = avformat_alloc_output_context2(&FormatContext, OutputFormat, nullptr, FileName);
if (ErrorCode < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Failed to allocate format context: %s", Error);
return false;
}
else if (!FormatContext)
{
Log("Failed to get format from filename: %s", FileName);
return false;
}
/* find the video encoder */
const AVCodec* Codec = avcodec_find_encoder(CodecID);
if (!Codec)
{
Log("Codec '%d' not found", CodecID);
return false;
}
/* create the video stream */
AVStream* Stream = avformat_new_stream(FormatContext, Codec);
if (!Stream)
{
Log("Failed to allocate stream");
return false;
}
/* create the codec context */
CodecContext = avcodec_alloc_context3(Codec);
if (!CodecContext)
{
Log("Could not allocate video codec context");
return false;
}
Stream->codecpar->codec_id = OutputFormat->video_codec;
Stream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
Stream->codecpar->width = Width;
Stream->codecpar->height = Height;
Stream->codecpar->format = AV_PIX_FMT_YUV420P;
Stream->codecpar->bit_rate = (int64_t)BitRate * 1000;
avcodec_parameters_to_context(CodecContext, Stream->codecpar);
CodecContext->time_base = { 1, FPS };
CodecContext->max_b_frames = 2;
CodecContext->gop_size = 12;
CodecContext->framerate = { FPS, 1 };
if (Stream->codecpar->codec_id == AV_CODEC_ID_H264)
av_opt_set(CodecContext, "preset", "medium", 0);
else if (Stream->codecpar->codec_id == AV_CODEC_ID_H265)
av_opt_set(CodecContext, "preset", "medium", 0);
avcodec_parameters_from_context(Stream->codecpar, CodecContext);
if (FormatContext->oformat->flags & AVFMT_GLOBALHEADER)
CodecContext->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
if ((ErrorCode = avcodec_open2(CodecContext, Codec, NULL)) < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Failed to open codec: %s", Error);
return false;
}
if (!(OutputFormat->flags & AVFMT_NOFILE))
{
if ((ErrorCode = avio_open(&FormatContext->pb, FileName, AVIO_FLAG_WRITE)) < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Failed to open file: %s", Error);
return false;
}
}
Stream->time_base = CodecContext->time_base;
if ((ErrorCode = avformat_write_header(FormatContext, NULL)) < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Failed to write header: %s", Error);
return false;
}
CodecContext->time_base = Stream->time_base;
av_dump_format(FormatContext, 0, FileName, 1);
// create the frame
{
Frame = av_frame_alloc();
if (!Frame)
{
Log("Could not allocate video frame");
return false;
}
Frame->format = CodecContext->pix_fmt;
Frame->width = CodecContext->width;
Frame->height = CodecContext->height;
ErrorCode = av_frame_get_buffer(Frame, 32);
if (ErrorCode < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Could not allocate the video frame data: %s", Error);
return false;
}
}
// create a color converter
{
ColorConverter = sws_getContext(CodecContext->width, CodecContext->height, AV_PIX_FMT_BGRA,
CodecContext->width, CodecContext->height, AV_PIX_FMT_YUV420P, 0, 0, 0, 0);
if (!ColorConverter)
{
Log("Could not allocate color converter");
return false;
}
}
bInitialized = true;
return true;
}
bool FMovieMaker::RecordFrame(uint8_t* BGRAData)
{
if (!bInitialized)
{
Log("Cannot record frames on an uninitialized Video Recorder");
return false;
}
/*make sure the frame data is writable */
int ErrorCode = av_frame_make_writable(Frame);
if (ErrorCode < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Could not make the frame writable: %s", Error);
return false;
}
/* convert the bgra bitmap data into yuv frame data */
int inLinesize[1] = { 4 * CodecContext->width }; // RGB stride
sws_scale(ColorConverter, &BGRAData, inLinesize, 0, CodecContext->height, Frame->data, Frame->linesize);
//Frame->pts = RecordedFrames++;
Frame->pts = CodecContext->time_base.den / CodecContext->time_base.num * CodecContext->framerate.den / CodecContext->framerate.num * (RecordedFrames++);
//The following assumes that codecContext->time_base = (AVRational){1, 1};
//Frame->pts = frameduration * (RecordedFrames++) * Stream->time_base.den / (Stream->time_base.num * fps);
//Frame->pts += av_rescale_q(1, CodecContext->time_base, Stream->time_base);
return EncodeFrame(false);
}
bool FMovieMaker::EncodeFrame(bool bFinalize)
{
/* send the frame to the encoder */
int ErrorCode = avcodec_send_frame(CodecContext, bFinalize ? nullptr : Frame);
if (ErrorCode < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Error sending a frame for encoding: %s", Error);
return false;
}
AVPacket Packet;
av_init_packet(&Packet);
Packet.data = NULL;
Packet.size = 0;
Packet.flags |= AV_PKT_FLAG_KEY;
Packet.pts = Frame->pts;
if (avcodec_receive_packet(CodecContext, &Packet) == 0)
{
//std::cout << "pkt key: " << (Packet.flags & AV_PKT_FLAG_KEY) << " " << Packet.size << " " << (counter++) << std::endl;
uint8_t* size = ((uint8_t*)Packet.data);
//std::cout << "first: " << (int)size[0] << " " << (int)size[1] << " " << (int)size[2] << " " << (int)size[3] << " " << (int)size[4] << " " << (int)size[5] << " " << (int)size[6] << " " << (int)size[7] << std::endl;
av_interleaved_write_frame(FormatContext, &Packet);
av_packet_unref(&Packet);
}
return true;
}
bool FMovieMaker::Finalize()
{
if (!bInitialized)
{
Log("Cannot finalize uninitialized Video Recorder");
return false;
}
//DELAYED FRAMES
AVPacket Packet;
av_init_packet(&Packet);
Packet.data = NULL;
Packet.size = 0;
for (;;)
{
avcodec_send_frame(CodecContext, NULL);
if (avcodec_receive_packet(CodecContext, &Packet) == 0)
{
av_interleaved_write_frame(FormatContext, &Packet);
av_packet_unref(&Packet);
}
else
break;
}
av_write_trailer(FormatContext);
if (!(OutputFormat->flags & AVFMT_NOFILE))
{
int ErrorCode = avio_close(FormatContext->pb);
if (ErrorCode < 0)
{
char Error[AV_ERROR_MAX_STRING_SIZE];
av_make_error_string(Error, AV_ERROR_MAX_STRING_SIZE, ErrorCode);
Log("Failed to close file: %s", Error);
}
}
if (Frame)
{
av_frame_free(&Frame);
Frame = nullptr;
}
if (CodecContext)
{
avcodec_free_context(&CodecContext);
CodecContext = nullptr;
}
if (FormatContext)
{
avformat_free_context(FormatContext);
FormatContext = nullptr;
}
if (ColorConverter)
{
sws_freeContext(ColorConverter);
ColorConverter = nullptr;
}
bInitialized = false;
return true;
}
void FMovieMaker::Log(const char* fmt, ...)
{
va_list args;
fprintf(stderr, "LOG: ");
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
fprintf(stderr, "\n");
}
主文件
#include "MovieMaker.h"
uint8_t FtoB(float x)
{
if (x <= 0.0f)
return 0;
if (x >= 1.0f)
return 255;
else
return (uint8_t)(x * 255.0f);
}
void SetPixelColor(float X, float Y, float Width, float Height, float t, uint8_t* BGRA)
{
t += 12.0f; // more interesting colors at this time
float P[2] = { 0.1f * X - 25.0f, 0.1f * Y - 25.0f };
float V = sqrtf(P[0] * P[0] + P[1] * P[1]);
BGRA[0] = FtoB(sinf(V + t / 0.78f));
BGRA[1] = FtoB(sinf(V + t / 10.0f));
BGRA[2] = FtoB(sinf(V + t / 36e2f));
BGRA[3] = 255;
}
int main()
{
FMovieMaker MovieMaker;
const char* FileName = "C:\\ffmpeg\\MyMovieMakerMovie.mp4";
int Width = 640;
int Height = 480;
int FPS = 30;
int BitRateKBS = 2000;
if (MovieMaker.Initialize(FileName, Width, Height, FPS, BitRateKBS))
{
int Size = Width * 4 * Height;
uint8_t* BGRAData = new uint8_t[Size];
memset(BGRAData, 255, Size);
for (float Frame = 0; Frame < 60; Frame++)
{
// fill the image data with something interesting
for (float Y = 0; Y < Height; Y++)
{
for (float X = 0; X < Width; X++)
{
SetPixelColor(X, Y, (float)Width, (float)Height, Frame / (float)FPS, &BGRAData[(int)(Y * Width + X) * 4]);
}
}
if (!MovieMaker.RecordFrame(BGRAData))
break;
}
delete[] BGRAData;
MovieMaker.Finalize();
}
}
如果我有添加AV_CODEC_FLAG_GLOBAL_HEADER如上所示标志的行，我会在输出中遇到各种问题ffprobe MyMovieMakerMovie.mp4。
C:\ffmpeg>ffprobe MyMovieMakerMovie.mp4
ffprobe version 4.2.2 Copyright (c) 2007-2019 the FFmpeg developers
built with gcc 9.2.1 (GCC) 20200122
configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
[h264 @ 000001d44b795b00] non-existing PPS 0 referenced
[h264 @ 000001d44b795b00] decode_slice_header error
[h264 @ 000001d44b795b00] no frame!
...
[h264 @ 000001d44b795b00] non-existing PPS 0 referenced
[h264 @ 000001d44b795b00] decode_slice_header error
[h264 @ 000001d44b795b00] no frame!
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001d44b783880] decoding for stream 0 failed
[mov,mp4,m4a,3gp,3g2,mj2 @ 000001d44b783880] Could not find codec parameters for stream 0 (Video: h264 (avc1 / 0x31637661), none, 640x480, 20528 kb/s): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MyMovieMakerMovie.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Duration: 00:00:01.97, start: 0.000000, bitrate: 20529 kb/s
Stream #0:0(und): Video: h264 (avc1 / 0x31637661), none, 640x480, 20528 kb/s, 30.51 fps, 30 tbr, 15360 tbn, 30720 tbc (default)
Metadata:
handler_name : VideoHandler
在不添加AV_CODEC_FLAG_GLOBAL_HEADER标志的情况下，我从 ffprobe 获得了干净的输出，但视频仍然无法播放。注意它认为帧速率是 30.51，我不知道为什么。
C:\ffmpeg>ffprobe MyMovieMakerMovie.mp4
ffprobe version 4.2.2 Copyright (c) 2007-2019 the FFmpeg developers
built with gcc 9.2.1 (GCC) 20200122
configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MyMovieMakerMovie.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Duration: 00:00:01.97, start: 0.000000, bitrate: 20530 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x480, 20528 kb/s, 30.51 fps, 30 tbr, 15360 tbn, 60 tbc (default)
Metadata:
handler_name : VideoHandler
解决方案
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