StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POHow to encode using the FFMpeg in Android (using H263)
text
Body
copied!<p>I am trying to follow the sample code on encoding in the ffmpeg document and successfully build a application to encode and generate a mp4 file but I face the following problems: </p> <p>1) I am using the H263 for encoding but I can only set the width and height of the AVCodecContext to 176x144, for other case (like 720x480 or 640x480) it will return fail.</p> <p>2) I can't play the output mp4 file by using the default Android player, isn't it support H263 mp4 file? p.s. I can play it by using other player</p> <p>3) Is there any sample code on encoding other video frame to make a new video (which mean decode the video and encode it back in different quality setting, also i would like to modify the frame content)?</p> <p>Here is my code, thanks!</p> <pre><code>JNIEXPORT jint JNICALL Java_com_ffmpeg_encoder_FFEncoder_nativeEncoder(JNIEnv* env, jobject thiz, jstring filename){ LOGI("nativeEncoder()"); avcodec_register_all(); avcodec_init(); av_register_all(); AVCodec *codec; AVCodecContext *codecCtx; int i; int out_size; int size; int x; int y; int output_buffer_size; FILE *file; AVFrame *picture; uint8_t *output_buffer; uint8_t *picture_buffer; /* Manual Variables */ int l; int fps = 30; int videoLength = 5; /* find the H263 video encoder */ codec = avcodec_find_encoder(CODEC_ID_H263); if (!codec) { LOGI("avcodec_find_encoder() run fail."); } codecCtx = avcodec_alloc_context(); picture = avcodec_alloc_frame(); /* put sample parameters */ codecCtx->bit_rate = 400000; /* resolution must be a multiple of two */ codecCtx->width = 176; codecCtx->height = 144; /* frames per second */ codecCtx->time_base = (AVRational){1,fps}; codecCtx->pix_fmt = PIX_FMT_YUV420P; codecCtx->codec_id = CODEC_ID_H263; codecCtx->codec_type = AVMEDIA_TYPE_VIDEO; /* open it */ if (avcodec_open(codecCtx, codec) < 0) { LOGI("avcodec_open() run fail."); } const char* mfileName = (*env)->GetStringUTFChars(env, filename, 0); file = fopen(mfileName, "wb"); if (!file) { LOGI("fopen() run fail."); } (*env)->ReleaseStringUTFChars(env, filename, mfileName); /* alloc image and output buffer */ output_buffer_size = 100000; output_buffer = malloc(output_buffer_size); size = codecCtx->width * codecCtx->height; picture_buffer = malloc((size * 3) / 2); /* size for YUV 420 */ picture->data[0] = picture_buffer; picture->data[1] = picture->data[0] + size; picture->data[2] = picture->data[1] + size / 4; picture->linesize[0] = codecCtx->width; picture->linesize[1] = codecCtx->width / 2; picture->linesize[2] = codecCtx->width / 2; for(l=0;l<videoLength;l++){ //encode 1 second of video for(i=0;i<fps;i++) { //prepare a dummy image YCbCr //Y for(y=0;y<codecCtx->height;y++) { for(x=0;x<codecCtx->width;x++) { picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3; } } //Cb and Cr for(y=0;y<codecCtx->height/2;y++) { for(x=0;x<codecCtx->width/2;x++) { picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2; picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5; } } //encode the image out_size = avcodec_encode_video(codecCtx, output_buffer, output_buffer_size, picture); fwrite(output_buffer, 1, out_size, file); } //get the delayed frames for(; out_size; i++) { out_size = avcodec_encode_video(codecCtx, output_buffer, output_buffer_size, NULL); fwrite(output_buffer, 1, out_size, file); } } //add sequence end code to have a real mpeg file output_buffer[0] = 0x00; output_buffer[1] = 0x00; output_buffer[2] = 0x01; output_buffer[3] = 0xb7; fwrite(output_buffer, 1, 4, file); fclose(file); free(picture_buffer); free(output_buffer); avcodec_close(codecCtx); av_free(codecCtx); av_free(picture); LOGI("finish"); return 0; } </code></pre>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload