37#define INBUF_SIZE 4096
39static void pgm_save(
unsigned char *buf,
int wrap,
int xsize,
int ysize,
45 f = fopen(filename,
"wb");
46 fprintf(f,
"P5\n%d %d\n%d\n", xsize, ysize, 255);
47 for (i = 0; i < ysize; i++)
48 fwrite(buf + i * wrap, 1, xsize, f);
60 fprintf(stderr,
"Error sending a packet for decoding\n");
69 fprintf(stderr,
"Error during decoding\n");
84int main(
int argc,
char **argv)
86 const char *filename, *outfilename;
100 fprintf(stderr,
"Usage: %s <input file> <output file>\n"
101 "And check your input file is encoded by mpeg1video please.\n", argv[0]);
105 outfilename = argv[2];
117 fprintf(stderr,
"Codec not found\n");
123 fprintf(stderr,
"parser not found\n");
129 fprintf(stderr,
"Could not allocate video codec context\n");
139 fprintf(stderr,
"Could not open codec\n");
143 f = fopen(filename,
"rb");
145 fprintf(stderr,
"Could not open %s\n", filename);
151 fprintf(stderr,
"Could not allocate video frame\n");
164 while (data_size > 0 || eof) {
168 fprintf(stderr,
"Error while parsing\n");
Libavcodec external API header.
int main(int argc, char *argv[])
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
static AVCodecContext * dec_ctx
static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, char *filename)
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
const AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder or encoder (when the AV_CODEC_FLAG_RECON_FRAME flag is used...
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
void av_parser_close(AVCodecParserContext *s)
int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int64_t pts, int64_t dts, int64_t pos)
Parse a packet.
AVCodecParserContext * av_parser_init(int codec_id)
#define AVERROR_EOF
End of file.
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
#define AV_NOPTS_VALUE
Undefined timestamp value.
main external API structure.
int64_t frame_num
Frame counter, set by libavcodec.
This structure describes decoded (raw) audio or video data.
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
This structure stores compressed data.