This source file includes following definitions.
- draw_horiz_band
- video_decode
- main
#include "libavutil/adler32.h"
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavutil/imgutils.h"
uint8_t *slice_byte_buffer;
uint8_t slice_byte_buffer_size;
int draw_horiz_band_called;
static void draw_horiz_band(AVCodecContext *ctx, const AVFrame *fr, int offset[4],
int slice_position, int type, int height)
{
int i;
const AVPixFmtDescriptor *pix_fmt_desc;
int chroma_w, chroma_h;
int shift_slice_position;
int shift_height;
draw_horiz_band_called = 1;
pix_fmt_desc = av_pix_fmt_desc_get(ctx->pix_fmt);
chroma_w = -((-ctx->width) >> pix_fmt_desc->log2_chroma_w);
chroma_h = -((-height) >> pix_fmt_desc->log2_chroma_h);
shift_slice_position = -((-slice_position) >> pix_fmt_desc->log2_chroma_h);
shift_height = -((-ctx->height) >> pix_fmt_desc->log2_chroma_h);
for (i = 0; i < height; i++) {
memcpy(slice_byte_buffer + ctx->width * slice_position + i * ctx->width,
fr->data[0] + offset[0] + i * fr->linesize[0], ctx->width);
}
for (i = 0; i < chroma_h; i++) {
memcpy(slice_byte_buffer + ctx->width * ctx->height + chroma_w * shift_slice_position + i * chroma_w,
fr->data[1] + offset[1] + i * fr->linesize[1], chroma_w);
}
for (i = 0; i < chroma_h; i++) {
memcpy(slice_byte_buffer + ctx->width * ctx->height + chroma_w * shift_height + chroma_w * shift_slice_position + i * chroma_w,
fr->data[2] + offset[2] + i * fr->linesize[2], chroma_w);
}
}
static int video_decode(const char *input_filename)
{
AVCodec *codec = NULL;
AVCodecContext *ctx= NULL;
AVCodecParameters *origin_par = NULL;
uint8_t *byte_buffer = NULL;
AVFrame *fr = NULL;
AVPacket pkt;
AVFormatContext *fmt_ctx = NULL;
int number_of_written_bytes;
int video_stream;
int got_frame = 0;
int byte_buffer_size;
int result;
int end_of_stream = 0;
draw_horiz_band_called = 0;
result = avformat_open_input(&fmt_ctx, input_filename, NULL, NULL);
if (result < 0) {
av_log(NULL, AV_LOG_ERROR, "Can't open file\n");
return result;
}
result = avformat_find_stream_info(fmt_ctx, NULL);
if (result < 0) {
av_log(NULL, AV_LOG_ERROR, "Can't get stream info\n");
return result;
}
video_stream = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
if (video_stream < 0) {
av_log(NULL, AV_LOG_ERROR, "Can't find video stream in input file\n");
return -1;
}
origin_par = fmt_ctx->streams[video_stream]->codecpar;
codec = avcodec_find_decoder(origin_par->codec_id);
if (!codec) {
av_log(NULL, AV_LOG_ERROR, "Can't find decoder\n");
return -1;
}
ctx = avcodec_alloc_context3(codec);
if (!ctx) {
av_log(NULL, AV_LOG_ERROR, "Can't allocate decoder context\n");
return AVERROR(ENOMEM);
}
result = avcodec_parameters_to_context(ctx, origin_par);
if (result) {
av_log(NULL, AV_LOG_ERROR, "Can't copy decoder context\n");
return result;
}
ctx->draw_horiz_band = draw_horiz_band;
ctx->thread_count = 1;
result = avcodec_open2(ctx, codec, NULL);
if (result < 0) {
av_log(ctx, AV_LOG_ERROR, "Can't open decoder\n");
return result;
}
fr = av_frame_alloc();
if (!fr) {
av_log(NULL, AV_LOG_ERROR, "Can't allocate frame\n");
return AVERROR(ENOMEM);
}
if (strcmp(codec->name, "flv") && strcmp(codec->name, "mpeg4") && strcmp(codec->name, "huffyuv")) {
av_log(NULL, AV_LOG_ERROR, "Wrong codec\n");
return -1;
}
byte_buffer_size = av_image_get_buffer_size(ctx->pix_fmt, ctx->width, ctx->height, 32);
byte_buffer = av_malloc(byte_buffer_size);
if (!byte_buffer) {
av_log(NULL, AV_LOG_ERROR, "Can't allocate buffer\n");
return AVERROR(ENOMEM);
}
slice_byte_buffer = av_malloc(byte_buffer_size);
if (!slice_byte_buffer) {
av_log(NULL, AV_LOG_ERROR, "Can't allocate buffer\n");
return AVERROR(ENOMEM);
}
memset(slice_byte_buffer, 0, byte_buffer_size);
slice_byte_buffer_size = byte_buffer_size;
av_init_packet(&pkt);
do {
if (!end_of_stream) {
if (av_read_frame(fmt_ctx, &pkt) < 0) {
end_of_stream = 1;
}
}
if (end_of_stream) {
pkt.data = NULL;
pkt.size = 0;
}
if (pkt.stream_index == video_stream || end_of_stream) {
got_frame = 0;
result = avcodec_decode_video2(ctx, fr, &got_frame, &pkt);
if (result < 0) {
av_log(NULL, AV_LOG_ERROR, "Error decoding frame\n");
return result;
}
if (got_frame) {
number_of_written_bytes = av_image_copy_to_buffer(byte_buffer, byte_buffer_size,
(const uint8_t* const *)fr->data, (const int*) fr->linesize,
ctx->pix_fmt, ctx->width, ctx->height, 1);
if (number_of_written_bytes < 0) {
av_log(NULL, AV_LOG_ERROR, "Can't copy image to buffer\n");
return number_of_written_bytes;
}
if (draw_horiz_band_called == 0) {
av_log(NULL, AV_LOG_ERROR, "draw_horiz_band haven't been called!\n");
return -1;
}
if (av_adler32_update(0, (const uint8_t*)byte_buffer, number_of_written_bytes) !=
av_adler32_update(0, (const uint8_t*)slice_byte_buffer, number_of_written_bytes)) {
av_log(NULL, AV_LOG_ERROR, "Decoded frames with and without draw_horiz_band are not the same!\n");
return -1;
}
}
av_packet_unref(&pkt);
av_init_packet(&pkt);
}
} while (!end_of_stream || got_frame);
av_packet_unref(&pkt);
av_frame_free(&fr);
avcodec_close(ctx);
avformat_close_input(&fmt_ctx);
avcodec_free_context(&ctx);
av_freep(&byte_buffer);
av_freep(&slice_byte_buffer);
return 0;
}
int main(int argc, char **argv)
{
if (argc < 2)
{
av_log(NULL, AV_LOG_ERROR, "Incorrect input: expected %s <name of a video file>\nNote that test works only for huffyuv, flv and mpeg4 decoders\n", argv[0]);
return 1;
}
if (video_decode(argv[1]) != 0)
return 1;
return 0;
}