Thanks Andrey. I'll paste my code below. All this does is read each frame
and convert it to a packed RGBA buffer.
I should also mention that I am building my app with MSVC++ 9.0 for Windows
(64-bit). I haven't tested it with other platforms/compilers.
// Main.cpp
//
#include <vector>
// Needed before including libav headers
//
#define __STDC_CONSTANT_MACROS
// Includes for libav
//
extern "C" {
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavutil/mathematics.h"
#include "libavutil/samplefmt.h"
#include "libswscale/swscale.h"
}
#define BUF_SIZE 2048
int main(int argc, char *argv[])
{
char lastError[BUF_SIZE];
int streamIndex = -1;
if (argc < 2)
{
printf("Usage: fftest inputfile\n");
return 1;
}
// Initialize Ffmpeg
//
::av_register_all();
::avformat_network_init();
::avcodec_register_all();
AVInputFormat *format = 0;
AVFormatContext *avFormatContext = 0;
// Open the stream and read the header
//
int ret = ::avformat_open_input(&avFormatContext,
argv[1],
format,
0);
if (ret < 0)
{
::av_strerror(ret, lastError, BUF_SIZE);
::printf("%s\n", lastError);
return 1;
}
// Retrieve stream information into streams field
//
ret = ::avformat_find_stream_info(avFormatContext, 0);
if (ret >= 0)
{
// Get the video stream
//
for (unsigned int i = 0; i < avFormatContext->nb_streams; ++i)
{
// Print info about each stream to stderr
//
::av_dump_format(avFormatContext, i, argv[1], false);
// Find the first video stream
//
if (avFormatContext->streams[i]->codec->codec_type ==
AVMEDIA_TYPE_VIDEO)
{
streamIndex = i;
break;
}
}
// Check if no video stream was found
//
if (streamIndex == -1)
{
::printf("No video stream found\n");
return 1;
}
}
else
{
::av_strerror(ret, lastError, BUF_SIZE);
::printf("%s\n", lastError);
return 1;
}
// Get pointer to the stream
//
AVStream *stream = avFormatContext->streams[streamIndex];
// Set up the video codec
//
AVCodec *codec = 0;
AVCodecContext *avCodecContext = 0;
if (stream->codec && stream->codec->codec_id != CODEC_ID_NONE)
{
// Get a pointer to the codec context (what the stream knows about the
codec)
//
avCodecContext = stream->codec;
// Find the appropriate video codec based on the stream info
//
codec = ::avcodec_find_decoder(avCodecContext->codec_id);
}
else
{
::printf("Codec not found\n");
return 1;
}
// Check if the codec was found
//
if (!codec || !avCodecContext)
{
printf("Could not find appropriate video codec\n");
return 1;
}
// Open codec
//
ret = ::avcodec_open2(avCodecContext, codec, 0);
if (ret != 0)
{
::av_strerror(ret, lastError, BUF_SIZE);
printf("Could not open codec: %s\n", lastError);
return 1;
}
// Get video dimensions
//
int width = avCodecContext->width;
int height = avCodecContext->height;
// Allocate frames in original color space and RGBA space
//
AVFrame *frame = ::avcodec_alloc_frame();
AVFrame *frameRgba = ::avcodec_alloc_frame();
if (frame == 0 || frameRgba == 0)
{
printf("Could not allocate frame\n");
return 1;
}
// Allocate RGBA buffer
//
std::vector<unsigned char> rgbaBuffer(::avpicture_get_size(PIX_FMT_RGBA,
width, height));
// Assign appropriate parts of buffer to image planes in frameRgba
//
ret = ::avpicture_fill((AVPicture *)frameRgba, &(rgbaBuffer[0]),
PIX_FMT_RGBA, width, height);
if (ret != rgbaBuffer.size())
{
printf("avpicture_fill returned incorrect # of bytes\n");
return 1;
}
SwsContext *swsContextRgba = ::sws_getContext(
width, height, avCodecContext->pix_fmt,
width, height, PIX_FMT_RGBA,
SWS_FAST_BILINEAR,
0, 0, 0);
if (!swsContextRgba)
{
printf("Error getting SwsContext\n", lastError);
return 1;
}
AVPacket packet;
bool eof = false;
// Begin reading frames
//
for (int i = 0; !eof; ++i)
{
printf("Reading frame %d... ", i);
int frameFinished = 0;
while (frameFinished == 0)
{
int ret = ::av_read_frame(avFormatContext, &packet);
if (ret == AVERROR_EOF)
{
// EOF has been reached
//
printf("EOF\n");
eof = true;
break;
}
else if (ret < 0 || packet.data == 0)
{
::av_strerror(ret, lastError, BUF_SIZE);
printf("%s\n", lastError);
return 1;
}
// Is this a packet from our video stream?
//
if (packet.stream_index == streamIndex)
{
// Decode video frame
//
ret = ::avcodec_decode_video2(avCodecContext, frame,
&frameFinished, &packet);
if (ret < 0)
{
::av_strerror(ret, lastError, BUF_SIZE);
printf("%s\n", lastError);
return 1;
}
// Did we get a video frame?
//
if (frameFinished)
{
// Convert the image from its native format to RGBA
// NOTE: assumes source format has 3 planes
//
uint8_t* const srcPtrs[3] = {frame->data[0], frame->data[1],
frame->data[2]};
int srcStrides[3] = {frame->linesize[0], frame->linesize[1],
frame->linesize[2]};
uint8_t* const dstPtrs[1] = {frameRgba->data[0]};
int dstStrides[1] = {frameRgba->linesize[0]};
::sws_scale(swsContextRgba, srcPtrs, srcStrides, 0, height,
dstPtrs, dstStrides);
// Free the packet that was allocated by av_read_frame
//
::av_free_packet(&packet);
}
}
// Free the packet that was allocated by av_read_frame
//
::av_free_packet(&packet);
}
printf("done\n");
}
// Free structures
//
::av_free(frame);
::av_free(frameRgba);
::avcodec_close(avCodecContext);
::av_close_input_file(avFormatContext);
::sws_freeContext(swsContextRgba);
return 0;
}
On Mon, May 28, 2012 at 3:45 AM, Andrey Utkin <
[email protected]> wrote:
> 2012/5/25 Gunner Beckwith <[email protected]>:
> > Hello,
> >
> > My problem is that av_read_frame(fmtContext, &packet) seems to return
> > AVERROR_EOF before the end of the file is reached. This is for a .ts file
> > with h264-compressed video. An interesting pattern is that it seems to
> > always return exactly 10 frames too early, no matter the length
> (#frames) or
> > size (resolution) of the video file.
> >
> > I am creating the MPEG-TS file by running the ffmpeg command:
> >
> > ffmpeg -f lavfi -i testsrc=s=640x480:r=30:d=2 -vframes 60 -vcodec libx264
> > FfmpegInputStreamTest.ts
> >
> > E.g., this creates a 60-frame sequence at 640x480 resolution.
> av_read_frame
> > always returns EOF after 50 frames. If I do a 300-frame sequence at
> 320x240,
> > it returns EOF after 290 frames.
> >
> > Can anyone think of ideas what might be going on?
>
> Please share your app source code so we investigate the issue the same way.
>
> --
> Andrey Utkin
> _______________________________________________
> libav-api mailing list
> [email protected]
> https://lists.libav.org/mailman/listinfo/libav-api
>
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